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The history of the genus Onychiurus is discussed. Four new Onychiurus species are described from North American caves: steinmanni and nathanieli from Colorado, reluctoides from Indiana, and furcisetosus from Virginia. Onychiurus reluctus Christiansen, 1961 is redescribed. A key for all of the known North American species is provided.

Ceratophysella richardi sp. n. is described from South Carolina, USA. Unusual characteristics of a new species (post antennal organ with posterior lobes not surrounding accessory boss, macrochaetae p2 on thoracic terga II-III set nearly in line with setae p1, setae m2 on thoracic tergum II sometimes present, setae p1 and p2 on abdominal tergum IV microchaetae and macrochaetae, respectively, and all body sensilla long) are intermediate between two genera and led the authors to synonymize MitchellaniaWray, 1953 with CeratophysellaBörner, 1932.

The suprageneric classification of the order Entomobryomorpha (families Isotomidae, Tomoceridae, Oncopoduridae, Actaletidae, Coenaletidae, Paronellidae, Entomobryidae, Microfalculidae, Oncobryidae, and Praentomobryidae) is examined and revised. The families are placed in four superfamilies: Isotomoidea; Coenaletoidea, new status; Tomoceroidea; and Entomobryoidea. One new subfamily, Capbryinae, and two new tribes, Nothobryini and Bessionellini, are proposed. Entomobryoidea is examined in more detail at the level of subfamilies and tribes. The characteristics used for this classification are discussed and a scheme is presented. The rationale for the divisions used is discussed.

A prior study involved 78 Collembola specimens preserved in Upper Cretaceous (Campanian) amber from Canada. This work deals with 109 specimens from the mid Cretaceous (Cenomanian or possibly slightly lower) of Myanmar, 37 of which have been identified to the generic level; 14 new species are described. Two species of the family Isotomidae are placed in previously described genera. One is placed in the Late Cretaceous genus Protoisotoma ( burma ), and one in the extant genus Proisotoma (s.l.) pettersoni . The remaining specimens are placed in 11 newly erected genera or as “Incertae sedis” taxa in the broadly construed families Sminthuridae, Isotomidae, and Neanuridae. The new genera are Sminthuridae (s.l.): Grinnellia , Sminthuricinus , Mucrovirga , and Sminthurconus ; Isotomidae: Villusisotoma (two species, V. brevis and V. longa ), Burmisotoma , Propachyotoma , and Protodesoria ; Neanuridae (s.l.) Protodontella . Two new genera ( Praentomobrya and Cretacentomobrya ) are placed in a new family (Praentombryidae), which is similar to the modern family Entomobryidae. Most of the extinct genera are very similar to modern genera. This similarity, along with the occurrence of an extant genus, suggests that a greater proportion of the Collembola of Myanmar (Burma) survived the end-Cretaceous than did taxa in Canada, even though the former are approximately 30 Ma older.

A new species, Homidia huashanensis, is described from Shaanxi Province, China. It is similar to the Korean species H. koreana Lee and Lee 1981 in the chaetotaxy of Abd. IV and setae of labial base and similar to H. amethystina (Borner, 1909) Yosii, 1942 in having two unpaired inner teeth on unguis, and in the number of rows of dental spines. It can be distinguished from the former by the larger number of unpaired teeth of the unguis, the coxal macrochaetae, and the chaetotaxy on the first abdominal segment (11–12 macochaetae vs. 9); and from the latter species by the larger number of rows of dental spines (3–5 vs. 1).

Three species of Collembola (Family Tomoceridae), Tomocerus (Tomocerus) folsomi Denis, 1929 and Tomocerus (Tomocerus) violaceus Yosii, 1956 and Tomocerus (Monodontocerus) modificatus Yosii, 1955, are reexamined. Tomocerus folsomi has had no modern description. Our study shows it to be clearly separated from other members of the subgenus Tomocerus s.s. by the combination of peculiar spinelets on the dental spines, multidentate lamellae mucro and a “principal” basal dental seta. Tomocerus s.s. violaceus is separated from other members of the subgenus by simple dental spines plus 3 or fewer setae on the tenaculum. The previously undescribed macrochatae are described and illustrated. Tomocerus (Monodontocerus) modificatus is recorded from China for the first time. While all the previous records were from caves, some of the Chinese specimens are from surface habitats. A number of previously undescribed features are described and illustrated.

The genus Pseudosinella is surveyed. The 11 species recorded from East Asia are reviewed. Seven of these are reported from China by the present authors (P. bellingeri, caoi, grinnellia, hui, mutabilis, tumula, and sexoculata). Rusek first described P. tridentifera from China; Deharveng described P. chiangdaoensis from North Thailand; P. octopunctata Borner is a widespread species; and P. petterseni Borner is a Holarctic species. A key to the Pseudosinella species of East Asia is given.

A new species, Homidia emeiensis, is described from Sichuan Province, China. It is similar to the Chinese species H. tiantaiensis Chen & Lin 1998 and to the Korean species H. minuta Kim & Lee 1995. The new species can be distinguished from the former by the much smaller number of macrochaetae on fourth abdominal segment (6–8 vs. 22–27) and from the latter by the much smaller number of dental spines (5–17 vs. 20–25).

We examined and keyed out the subgenera of the genus Lepidocyrtus mostly created by Yoshii. Although many of these subgenera of the genus Lepidocyrtus are difficult to apply in Europe, America, and Africa, they are easily applicable in East and Southeast Asia. The species of Southeast Asia are placed in these subgenera and a key to the subgenera is provided. A new species, Lepidocyrtus (Lanocyrtus) felpei from Xinjiang, People's Republic of China, is described and the species Lepidocyrtus (Lanocyrtus) fimetarius Gisin is redescribed. Although the Lepidocyrtus fauna of the whole of East Asia differs from the Holarctic fauna, the Central and Northeast Asian fauna are similar in subgeneric make up to the North American fauna, slightly less similar to the European fauna, and totally unlike the Southeast Asian fauna.

A new species, Tomocerus (Tomocerina) tianshanensis, from Xinjiang of northwest China is described. It is distinguished from other members of the subgenus by the presence of intermediate mucronal teeth, single trochanteral organ setae on the trochanter, no macrochaetae on the posterior third of the head and strongly clavate tenet hairs. It is most similar to the Japanese species T. aokii Yosii 1972 and the Chinese species T. yiliensis. A diagnostic table and key to the subgenus Tomocerina are provided.

A new collembolan species, Pseudosinella hui, is described from a cave in Guilin, Guangxi, China. The species is most similar to a group of four European and one Nearctic species characterized by a ciliate labial M1 macrochaeta and lack of seta a on the second abdominal segment. They share a number of features including presence of eyes and lack of thoracic macrochaetae.

Aims Our objective was to identify client characteristics and other factors associated with pre-treatment drop-out by people with marijuana dependence. Design and participants Data from the Marijuana Treatment Project's screening assessment were used to examine correlates of pre-treatment drop-out. Information from all eligible study participants (n = 813) (i.e. those who were interested in receiving treatment for their marijuana dependence and were determined to be eligible for the randomized treatment efficacy trial) was used to examine differences between the 450 participants who initiated treatment (by enrolling in the trial) and the 363 individuals who declined enrollment. Setting The study was conducted at three community-based outpatient treatment facilities in Farmington, CT, Seattle, WA and Miami, FL. Measurements The information gathered in the screening interview included demographic characteristics, residential stability variables, employment and education history and referral source. Substance use variables included the number of days and the number of times per day marijuana was used, self-perceived dependence on marijuana, alcohol or other drugs, other drug use history and current treatment (i.e. substance abuse, medical, psychiatric) situation. Findings Stepwise logistic regression was conducted to confirm variables associated with treatment initiation in bivariate analyses. Pre-treatment drop-out was associated with being younger, unmarried, unemployed, less educated and Asian American or Native American. It was also associated with self-perceived dependence on marijuana and use of other drugs. Conclusions By recognizing demographic and substance use factors that may serve as barriers for individuals accessing treatment for marijuana dependence, clinicians may target clients with these characteristics proactively to encourage treatment initiation and subsequent attendance.

A new Chinese species of Collembola, Sinella (Coecobrya) liui, is described. It is closely related to S. (C.) tibetensis and huangi, but different in the chaetotaxy of the abdomen.

Previously only one specimen of springtail (Collembola) has been described worldwide from the Cretaceous. The present work reports the results of an examination of seventy-eight collembolan specimens from Canadian Upper Cretaceous amber. Sixty-three specimens have been identified at the generic level, none of which belongs to extant genera. All are placed within eight newly erected genera. Most of these specimens belong to a single new genus, Protoisotoma, of the family Isotomidae. Also included are members of the broadly construed families Sminthuridae, Neanuridae, and Tomoceridae. Re-examination of the type of Protentomobrya reaffirms its separate familial status. One additional specimen of an undescribed genus is placed in a new family. These data support a probable extinction of the Canadian arboreal Collembola fauna at the end of the Cretaceous.

Presently, a single specimen of Collembola has been described from the Cretaceous period. The present work describes the results of examination of over 70 specimens from Canadian Cretaceous amber. 63 specimens could be identified generically and none of these belonged to extant genera. All could be placed in one or another of 7 undescribed genera. Most of the specimens belong to a single undescribed genus of the family Isotomidae. Also included are members of the families Sminthuridae s.l., Neanuridae s.l., and Tomoceridae, Reexamination of the type of Protentomobrya reaffirms the separate familial status. In addition one additional specimen of an undescribed genus cannot be placed in extant families.

A general overview of the subgenus Coecobrya Yosii 1956 of the genus Sinella Brook 1892, a table of species characteristics, and a key to the world species are given. The identity of the species C. caeca Schott 1896 and tenebricosa Folsom 1902 is also discussed. Four new species of the subgenus from China are described: C. communis, tibetensis, huangi , and oligoseta .

We estimate that over 90% of Collembola species now living in the Hawaiian islands have been recorded, but the distribution of the fauna on individual islands is less well known. The relative number of species on the different large islands, except for Hawaii, is similar to that of most other groups of organisms. It appears that most species of Collembola could find suitable conditions on most islands; the subgenus Entomobryoides may be an exception. Endemicity appears to be related to age of the region, to habitat type, and perhaps to altitude. The Hawaiian fauna appears to have been recruited primarily from North America and temperate Asia, with tropical southeast Asia providing a smaller component; Western North America appears to be the main source for exemic species, and temperate Asia for the ancestors of endemic forms. Modes of immigration are uncertain, but ocean transport seems most likely for endemies of North American and Oriental origin, especially mobile members of the Entomobryidae ...

The genus Sinella is discussed and major changes in the taxonomy of the genus are made involving new criteria and a re-examination of old criteria. A key to all world species is given. This new system is applied to the members of the genus Sinella s.s. found in China. Ten new species of the subgenus Sinella s.s. are described: affluens, browni, fuyanensis, insolens, plebia, qufuensis, quinocula, sineocula, triocula, and trogla.

Publisher Summary This chapter discusses collembola or springtails which comprise one of the most widespread and abundant groups of terrestrial arthropods. Collembola have three thoracic segments and six or fewer abdominal segments, including a telson consisting of a dorsal and two ventral valves surrounding the anus. There are typically four antennal segments, each with musculature. Collembola vary enormously in form and somewhat in internal anatomy, but all lack malpighian tubules and most have paired labial nephridia that empty into the ventral groove at the base of the labium. One universal and unique feature is the ventral tube or collophore–—an istally weakly paired projection from the first abdominal segment with membranous diversity of form equal to that seen in any other order of insects. Collembola rarely interact overtly with humans. There are no parasitic Collembola and they are not known to transmit any disease. Collembola play an important role in the development and maintenance of healthy soils, but this is not generally appreciated.

This paper reports the results of a long-term survey of the invertebrates living in caves and other subterranean habitats in the Upper Mississippi River Valley, particularly in the region frequently but erroneously called the Driftless Area. Sixteen troglobitic species are known: two flatworms, two amphipods, one isopod, four spiders, one mite, and six collembolans. The terrestrial troglobite fauna probably represents cave invasion and isolation following Early Pleistocene glaciation, and demonstrates that the caves were habitable while the region was at the margin of Late Pleistocene glaciations. The groundwater troglobite fauna may have survived in situ while the region was covered by glacial ice in the Early Pleistocene. The troglophile fauna consists of at least 78 species, and these species may or may not have come into the region since the Wisconsinan glaciation recession. The presence of troglophile species in a particular cave is highly sporadic.

Type specimens of Desoria brucealla (Wray), a western North American species, are transferred to Misturasotoma n.gen. The new genus differs from Desoria, Heteroisotoma, Isotoma, and Parisotoma by the following combination of characters: eyes absent, tibiotarsi with 11 setae in distal whorl, tenaculum with 9–15 setae, manubrium with apical spinelike setae, mucrones quadridentate, macrochaetae smooth, and sensilliform setae of abdominal segments IV and V short.

A new species of Entomobryidae, Homidia pentachaeta, is described from China. It is unique in the presence of 5 lateral macrochaetae on each side of abdominal segment 3.

A new species of Arrhopalites is described from China. It is distinguished by lack of eyes and absence of short spines on anogenital segment.

(1959). Repression and Psychopathology. Journal of Projective Techniques: Vol. 23, No. 4, pp. 412-416.

The nine species known to occur in Nearctic caves are keyed and seven of these are described and illustrated. The other two are edaphic forms, rarely found in such situations. Except for S. cavernarum (Packard) ( = Entomobrya lucifuga Folsom), which ranges from Pennsylvania to eastern Missouri, each truly cave-dwelling species has a very limited known distribution within an overall area extending from western Virginia to the Mississippi River and from south-central Indiana to northern Alabama. New species are: S . alata , S . avita , S . barri , and S . krekeleri . S. cavernarum var. basidens Bonet is raised to specific status, and Parasinella Bonet is synonymized under Sinella Brook.

ContextCognitive impairments are associated with long-term cannabis use, but the parameters of use that contribute to impairments and the nature and endurance of cognitive dysfunction remain uncertain.ObjectiveTo examine the effects of duration of cannabis use on specific areas of cognitive functioning among users seeking treatment for cannabis dependence.Design, Setting, and ParticipantsMultisite retrospective cross-sectional neuropsychological study conducted in the United States (Seattle, Wash; Farmington, Conn; and Miami, Fla) between 1997 and 2000 among 102 near-daily cannabis users (51 long-term users: mean, 23.9 years of use; 51 shorter-term users: mean, 10.2 years of use) compared with 33 nonuser controls.Main Outcome MeasuresMeasures from 9 standard neuropsychological tests that assessed attention, memory, and executive functioning, and were administered prior to entry to a treatment program and following a median 17-hour abstinence.ResultsLong-term cannabis users performed significantly less well than shorter-term users and controls on tests of memory and attention. On the Rey Auditory Verbal Learning Test, long-term users recalled significantly fewer words than either shorter-term users (P = .001) or controls (P = .005); there was no difference between shorter-term users and controls. Long-term users showed impaired learning (P = .007), retention (P = .003), and retrieval (P = .002) compared with controls. Both user groups performed poorly on a time estimation task (P

At the present time virtually nothing has been published concerning the cave collembolans of North America. As simple proof of this, a bibliography of North American cave Collembola contains less than 30 entries, most of which are antiquated or mere listings of one or two erroneously identified species in a cave fauna of Blank Cave. The only general survey is that of Packard (1888) which encompassed less than one percent of the actual fauna and, from a taxonomic viewpoint, is either useless or seriously damaging. In addition to the work of Packard, various forms were described by Banks (1897). The accuracy of these descriptions can be measured if we consider that they were made generally with the use of a hand lens upon specimens often less than a millimeter in total size. The only adequate works devoted solely to North American cave forms are those of Denis (1929) upon Oregon material collected by Silvestri, of Delamare Deboutteville (1949) upon material from a few caves in Alabama and Tennessee collected by Henrot, and of Bonet (1934) upon material largely from a few Kentucky and Virginia caves. All of these works were published in European journals and are in French. In addition, several authors (Mills 1934, 1948, Bonet 1943, Wray 1952, and Christiansen 1958) have described single cave species from the United States in larger works concerned with other groupings. It is not possible to obtain a view of the cave Collembola fauna of the United States from this bibliography; however, work now in press, or in progress, will greatly increase our records in the genera Sinella (Christiansen, 1960) and Pseudosinella (in preparation). Much of the cave area of the United States is still virtually untouched from the standpoint of collembolans, and experience has shown that the simple statement that "no collembola occur" is no indication of the presence or absence of these animals. In personal experience Collembola have been found in about two-thirds of the caves previously indicated to have none. Even the most astute collector may pass up these minute forms without experience and exhaustive search, or use of berlese extraction. At the present moment only the southeastern quadrant of the country has relatively complete collections, but examination of these, combined with the spotty collections from other parts of the country permits a rough guess as to the probable composition of the fauna. The following genera are known to occur in American caves

Cave collembola furnish excellent material for the study of evolution. This is the result of the limited nature of geographical movement between caves and the limited selective pressure of cave life resulting in the persistence of primitive forms in caves. Early studies have established both the nature of large scale evolution in cave forms and the relationship between behavior and form in this process (Christiansen, 1961; 1965). All of these studies have dealt with large scale changes involving clearly separated forms. In order to examine the small scale changes which have occurred in the caves, the geographical variation of Pseudosinella hirsuta (Delamare) and P. violenta (Folsom) in caves was analyzed in detail. An additional study of surface population variation in P. violenta is in progress. Pseudosinella hirsuta is the most variable troglobitic form of the genus in North America. It has been found in caves of Kentucky, Tennessee, Alabama, Georgia, and Virginia (see Fig. 1). The variation is extensive, so that some forms superficially resemble P. argentea (Folsom) and others resemble P. christianseni (Salmon) with all gradations in between. The species is highly cave-adapted and apparently has undergone extensive evolution within caves. Pseudosinella violenta is a cave troglophile that has invaded extensively the caves of the Edwards Plateau and adjoining regions of Texas. It has reached neither the stability nor the adaptations of P. hirsuta. It is in the early phases of the second stage of cave adaptation, as described by Christiansen (1961). P. hirsuta is in the beginning of the third and final phase of cave adaptation. In this first publication of these studies we shall deal with the variations in P. hirsuta. Subsequent papers will analyze the variation in P. violenta.

The study of evolution has always presented an exciting challenge and a series of very serious problems. Caves furnish an environment in which most of these problems can be avoided. First, the arthropod fauna of the caves is such that a living record often remains of virtually every stage in any evolutionary process which has occurred. Jeannel almost 50 years ago first noted this and said that caves were filled with living fossils. Second, caves furnish us with what is a natural evolutionary laboratory in which the evolutionary pressures are at the same time more simple and more compelling than those that we see in most surface areas. Thus caves furnish an ideal region for the study of the processes of evolution. For the past six years I have spent some time examining the evolution of one group of cave arthropods, the Collembola. Although the Collembola form an important part of the soil fauna they are poorly known among non-specialists. Fig. 1 gives an idea of the overall structure of the group concerned in this study. These animals are generally quite small. None of the forms I shall discuss here exceeds five mm. in length. The unique furcula at the end of the abdomen can be used for jumping, if the animals are hard pressed. Collembola are widely varied in both form and habitat, and are found from Antarctica to Nova Zemlya. They are common in caves and often occur in large numbers. In an earlier work (Christiansen, 1961), I showed how the distinctions between cave-dependent and cave-independent characteristics made it easy to map the phylogenies of the various groups with considerable confidence. One of the conclusions of this study was that there is an immense amount of convergence in the evolution of cave-dependent characteristics of cave Collembola. The conclusions drawn from the phylogenetic studies were amply reinforced by the data of zoogeography and relative dominance of the different forms. I also pointed out varying levels of preadaption in new cave invaders and the probable relationship between the modification of the foot complex and the increasing adaptation for locomotion over wet surfaces and standing water. Some questions were left unanswered by this work. First, what is the exact nature of behavioral evolution? Second, what is the relationship between these behavioral adaptions and the morphological changes? It is entirely possible that the cave species which are more primitive in morphological terms had compensated for this by extensive behavioral evolution. The present paper is an attempt to further clarify these problems in the subfamily Entomobryinae, where the changes involved are most extensive.

DETAILED studies of geographic vari.1/ ation in the members of the order Collembola are almost unknown. The closest approach to this type of work has been the study of color forms of Sira platani by Handschin (1926), and the various incidental notations in monographic works such as Stach's classic on the Isotomidae (1947), or Delamare's work upon termitophiles and myrmecophiles (1948). It is essential to understand the nature of the geographic variation within the group if any valid judgment is to be made concerning the real value of the various criteria now used to distinguish species in the Collembola. In the work described below an attempt was made to study all visible geographic variation within one species. One of the major objections which has been raised concerning the subspecies concept is that it is applicable in most cases only if a small part of the total of geographically variable characters is considered. According to this view the net result of the general acceptance of the subspecies idea is to overemphasize the most obvious type of geographic variation while inhibiting the study of the more complicated types. The evidence presented below supports such a thesis, because subspecies of guthriei could be created with little difficulty on the basis of any one of several geographically variable characters. However, when an attempt is made to study all characters exhibiting visible geographic variations within the species, any attempt to utilize the subspecies leads only to confuWsion. Entomobryoides guthriei is the commonest species of the genus in the western part of North America. It is common over the whole of the western third of the United States from the eastern foothills of the Rockies to the west coast. Scattered populations are found east to the Mississippi. It can readily be distinguished from the generally eastern E. purpurascens by differences in the external labial setae, by the male genital plate, and in some cases by the coloration and the structure of the ungues (see Fig. 1). E. guthriei is primarily an animal of the middle elevations, although it may occasionally be found as high as 13,000 feet, or more rarely on the slopes of low lying hills. The ecological factors controlling its distribution are still unknown. Throughout its range it displays considerable variation. To obtain some idea of the characters likely to display geographic variation, three populations-one from South Dakota, one from New Mexico, and one from Coloradowere studied exhaustively. This study re