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Rumen contents were obtained from 23 white-tailed deer (Odocoileus virginianus), located in the eastern portion of central Ohio. Samples were taken during late fall and winter over a 4-yr period, 1986–1990. Protozoan numbers ranged from 0.002 to 7.25 × 106 per ml of rumen contents, with a mean of 2.96 × 106. Six deer had protozoan concentrations higher than any values previously reported in ruminants. In all 23 animals, Entodinium dubardi was the only ciliate protozoan species present.

SYNOPSIS. Diplodinium flabellum, previously described on the basis of its occurrence in rumen contents from 3 hosts of Bos indicus, has been observed in domestic sheep. Numbers of this species were quite high, constituting up to 18.8% of the total fauna in one instance. Diurnal changes in numbers for sheep fed once daily were similar to the cycles reported for other Ophryoscolecids. No obvious relationship was found between the occurrence and numbers of D. flabellum and other genera of rumen ciliates. Two new morphologically distinct forms of this species were observed, one without any spines on the posterior left side and one with a single spine. This is in contrast to the original species description in which 2 spines occur on the posterior left side. Intermediate forms were observed which connected the 3 morphological types, indicating their conspecific relationship. It is proposed that the species description for Diplodinium flabellum be emended to include a total of 3 subspecies: Diplodinium flabellum Kofoid and MacLennan, 1932 flabellum subsp. n.; Diplodinium flabellum aspinatum subsp. n.; and Diplodinium flabellum monospinatum subsp. n. Considerable variation in the shape and length of the caudal fan was observed in specimens of the subspecies aspinatum. In three of the four sheep studied, the subspecies aspinatum predominated, while the species monospinatum was highest in the fourth animal. D. flabellum flabellum occurred in very low numbers, ranging from 0 to 2.5% of the total species number.

SYNOPSIS. Six protozoa-free sheep, 3 fed alfalfa hay and 3 fed a concentrate diet, were inoculated with rumen contents from a steer fed the same alfalfa hay. All 24 species of protozoa in the inoculum became established in the sheep fed alfalfa hay, while only 9 species established in the sheep fed concentrate. Percentage species composition in the alfalfa-fed sheep was fairly similar to that of the inoculum. Rumen volumes of the alfalfa hay-fed sheep were significantly higher than those of the concentrate-fed sheep; however, fluid turnover rates were similar. Total protozoan numbers per ml of rumen contents were significantly higher in the concentrate-fed sheep, but after adjustment for rumen volume, there was no significant difference in the total number of protozoa in the rumen.

SYNOPSIS. In many hypotrich ciliate protozoa there are at least 6 possible categories of ciliary structures: right marginal cirri, left marginal cirri, fronto-ventral-transverse cirri, membranelles, and 2 oral membranes. This report describes the kinetosomes, fibrils and microtubules which make up the cytoplasmic portion of these structures in Gastrostyla steinii. Altho light microscope studies have revealed significantly different infraciliature for the 3 classes of cirri, the fine structure of these locomotor organelles indicates that they have a remarkable number of homologous structures. There is also a number of apparent homologies between the cirri of this organism and ciliary structures of both more primitive and more highly evolved ciliates. The oral ciliature of G. steinii is analyzed and compared to that of other spirotrichs for clues to the phylogeny of the hypotrichs. Function of the infraciliature is considered briefly.

SYNOPSIS. Confusion has long existed in the literature concerning both the taxonomy and the nomenclature of ciliates belongin: to the astomatid family Haptophryidae. Most of the controversy has centered around the names and concepts of “Haptophrya” and “Sieboldiellina.” The latter name, widely used for certain species found as parasites (endocommensals) of turbellarians, must fall as a junior synonym of the former, which has commonly been restricted to the astomatous ciliate parasites (endocommensals) of various amphibians But the species of “Haptophrya” are then left without a generic vehicle, since Haptophrya Stein, 1867, must, in effect, be used to replace Sieboldiellina Collin, 1911, as the proper generic name of the turhellarian parasites Fortunately a name is available for the amphibian species: Cepedietta Kay, 1942. The problem is further complicated because of the recognition of subfamilial groups, the name of one of these having been formed from Sieboldiellina and having become associated with certain species parasitic in turbellarians. With the realization that, by the international rules of zoological nomenclature, Haptophrya must be used with reference to these particular turbellarian parasites, the subfamilial name associated with the amphibian forms must be changed. We propose Cepediettinae n. nom. in solution of this particular problem. We recognize a third subfamily, Ckpkde's Lachmannellinae, to contain the three remaining acceptable genera comprising the family Haptophryidae: Anndophrya, Lachmanndla, and Steinella. At the generic and specific levels numerous errors of a nomenclatural nature have been committed in the older literature, many unwittingly perpetuated in recent papers. These are all corrected in the present work. For the sake of future clarity we have included a series of figures, both original and from the literature, and have designated neotypes of the two principal species involved in the overall controversy.

SYNOPSIS. Stomatogenesis or new mouth formation sensu lato repnts an explicit example of a major morphogenetic phenomenon le life cycle of most ciliate Protozoa. Investigations of the process a number of approaches may yield data of considerable value. The present paper 3 such approaches are treated in some detail. udies of stomatogenesis can be of importance in providing addial information of significance on the structure and physiology a given organism. Five major types or categories of stomatoesis in ciliates are recognized. These are defined and discussed. search related to such an intrinsic value of the phenomenon the K carried out is generally only descriptive, and the most importechnic employed is some method of silver impregnation. a comparative approach is used, then attention may be focused possible homolegies in stomatogenesis as it occurs in diverse ies of ciliates. Such data are (or potentially are) of value not in the practical taxonomy of the organisms involved but also onsideration of phylogenetic and evolutionary interrelationships ing the higher groups comprising the entire subphylum Ciliophora. Such application of comparative studies may well become a very fruitful approach to certain problems in ciliate phylogeny; 2 examples are discussed briefly. Silver impregnation technics are again indispensable. Perhaps stomatogenesis will prove most valuable in the hands of developmental biologists who are seeking to solve 2 of the most intriguing problems in cell biology today: the exact origin of new kinetosomes (or centrioles), and their precise morphogenetic role in the life cycle of a cell or unicellular organism. Since this third approach to the study of stomatogenesis is of necessity a dynamic one, the researcher must employ sophisticated experimental technics to obtain data at the molecular and macromolecular levels of both organization and function. Some progress in this area has already been made, but the availability of “ideal” organisms has perhaps not been as widely realized as it should. Certain of the “higher” ciliates have a mode of stomatogenesis which would lend itself beautifully to fruitful investigation of problems concerning both replication or neoformation of kinetosomes and their possible role in fibrillogenesis in unicellular organisms.

SYNOPSIS. Chemical procedures remove some of the outer 3 limiting membranes of 2 ciliate protozoa, Euplotes eurystomus and Tetrahymena pyriformis, and reveal sheets of microtubules in their ectoplasm for SEM study. This greatly enhances the analysis of the 3-dimensional geometry of these sheets, as is shown especially for E. eurystomus. In this organism, sheets of microtubules can readily be observed and described as they course through or around parts of the oral apparatus and other 3-dimensionally complex regions.

An unknown, ninhydrin-positive substance detected on paper chromatograms of the endogenous metabolites of mixed rumen ciliate protozoa was isolated and purified by column chromatography with ‘Dowex’ 50-X8 resin and identified as 2-aminobutanoic acid (α-amino-n-butyric acid) on the basis of elementary analysis, mass spectrometry, paper chromatography, infrared spectrometry, and melting point.

SYNOPSIS. An international collection center for type-specimens of protozoa belonging to the subphylum Ciliophora has been set up at the University of Illinois through the cooperation of the Museum of Natural History there. The writer will act as curator of slides deposited in this central collection. Syntypes are solicited from all protozoologists interested in ciliate taxonomy who may possess such specimens. In accordance with provisions of Article 72 of the International Code of Zoological Nomenclature, all material received will be properly handled and indexed and regarded as “the property of science”; preparations will be made available on loan to qualified workers anywhere who need them temporarily for research purposes. Existence of such a type-slide collection should aid in alleviation of a growing number of vexatious problems in the systematics of the ciliate Protozoa at specific and generic levels.

SYNOPSIS. Ciliate protozoa from the rumen of the tsessebe, Damaliscus lunatus lunatus, all belong to the family Ophryoscolescidae and no holotrichs were found in any of the 16 animals. Eighteen species were identified of which Entodinium fyferi sp. n., Enoploplastron garstangi sp. n. and Epidinium lunatus sp. n. are new and have been described for the first time. A short redescription of Eremoplastron gigantium Kofoid & MacLennan is given.