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Genus Dichelonycha Harris.–Labrum transverse, lanceolate, scarcely emarginate. Mandibles short, trigonal, incurved, toothless, acute : molary space transverse, furrowed. Maxillæ minute, linear, bidentate, with short teeth. Labium subquadrangular, not distinct from the mentum. Palpi maxillary four-jointed ; first joint very minute ; second longer than the third, obconical; third trianguler; last joint as long as the three others together, very large, subsecuriforrn. Palpi labial three-jointed; joints short, subfiliform ; last truncated.

The size and beauty of the Longhorns are in themselves sufficient to render them objects of interest to a beginner; adding to this the fact of the great abundance of certain species and the destructive work of their larvæ, we can readily understand their importance to all who are in any way interested in Entomology, whether as a pleasant recreation for leisure hours or a serious pursuit for gain. Although usually easily recognized by sight, the family is, as stated by Dr. Leconte, almost impossible to define. The tarsi are apparently four-jointed, the fourth joint being very small and connate with the fifth. The antennæ are usually very long, especially in the males, filiform or serrate, often borne on large frontal tubercles. The eyes are frequently deeply emarginate. Tibial spurs are present. The larvæ are grub-like, living in burrows or chambers which they excavate for themselves in the woody tissues or in the pith of plants, the pupa resting in a cell constructed by the larva in its gallery.

The metabolism of the imaginal discs of wild type, miniature, vestigial, and four-jointed varieties of Drosophila was investigated using the Cartesian diver ultramicrorespirometer. Wild type and vestigial wing disc respiration is inhibited by cyanide and azide and thus is mediated by an iron or copper porphyrin system, presumable cytochrome-cytochrome oxidase. Respiration is also inhibited by certain hydroxynaphthoquinones, believed to inactivate some enzyme between cytochromes b and c. The respiration of the vestigial and miniature wing discs is increased to normal by the addition of ascorbic acid and to a lesser extent by p-phenylenediamine and hydroquinone, hence the cytochrome oxidase and cytochrome c systems of vestigial and miniature wing discs are normal and the effects of these genes are on enzymes below cytochrome c in the respiratory chain. The respiratory enzymes of the developing imaginal discs of insects are similar to those of a wide variety of cells from bacteria to mammals. The correlation of these biochemical findings with embryological studies of the discs is discussed.

The Cucujidæ constitute a small family of beetles of depressed, often elongate form, the antennæ lengthened in many species, giving them a somewhat characteristic appearance, which, while recalling the Cerambycidæ, renders them, nevertheless, easily recognized. They may be technically distinguished from the allied Clavicorn families by the long elytra, the five-jointed tarsi (the hind ones sometimes only four-jointed in the males), the rounded or oval anterior coxæ, the middle ones with externally open cavities and the posterior separate. The ventral segments are sub-equal in length. The larvæ, so far as known, are flattened grubs, with distinct antennæ and several ocelli; the terminal segments often with hooks or tubercles.

The maxillary palpi of Osmia(sens. lat.) are given by most authors as four-jointed. I have examined the maxillary palpi of sixteen species in this group, and find in every instance that these palpi are five-jointed. The first joint is usually small, sometimes globular in shape, and visible with a hand-lens only under very favorable conditions. The following species were examined: From the coll. of the State Agr'l College of Colorado?O. armaticeps; Cr.; Coloradensis, Cr.; dubia, Cr.; fulgida, Cr.; integra, Cr.; lignaria, Say, and mandibularis, Cr., all from Colorado.

Protandrenopsis, new genus. ? Labial palpi four-jointed, 1 about twice as long as 2?4 together, 2?4 slightly decreasing in length; maxillary palpi 6-jointed, 1 and 2 subequal, longer than any of the following joints; 3, 5 and 6 subequal, 4 slightly longer; tongue long, lanceolate; mandibles simple; labrum transverse, process of labrum large, almost covering labrum; fove? present, small; stigma large, well developed, nearly two thirds the length of the obliquely truncate, subappendiculate marginal cell, which is about as long as the two submarginals together; second submarginal fully one-third longer than the first, receiving the first recurrent nervure about one-third from base and the second near apex; median cell along the median nervure, a little longer than the submedian, the transverse median nervure joining the median just before the origin of the basal nervure; scopa on posterior tibi? first joint of tarsi and on venter.

Silpha Coloradensis, n. sp.? Form of in?qualis, but more elongae, black, except the tip of the abdomen, which is orange-rufocus; above clothed with short black hairs. Head densely punctate, the punctures regular over the greater part of the surface, those in front of the inter-antennal line smalll and less distinct; occipital transeverse impression deep; labrum short, broadly emarginate; antenn? black, club four-jointed, the last three joints pubesecnt, the terminal one longer, compressed, tip sinuately rounded. Thorax about one one-half times as broad as long, narrowed anteriorly, sides broadly arcuate in front, more suddenly so behind, basal lobe slightly and very broadly emarginate. Surface somewhat irregular, densely and very regularly punctate, sides somewhat flattened. Scutellum slightly concave, densely puncutred. Elytra as wide as the thorax and fully twice as long, the sides nearly parallel, outer margins distinctly reflexed, apices conjointly rounded, but sinuate externally, punctuation less dense than that of the thorax, each puncture with a recumbent hair.