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Show 83 for their swollen hind thighs, enabling them to spring to great distances It appears to belong to the group of Oedionychites Chap., in which the last tarsal joint has a more or less prominent bulbous expansion on the hind legs; but it differs from any of the genera described by Ghapuis in the nature of this expansion, as well as in other tarsal peculiarities. The basal joint of these hind tarsi is moderately long and cylindrical, scarcely larger at the apical than at the distal extremity; the second and third joints are subequal, the latter slightly the larger, together as long as the basal joint, moderately lobate, the lobes pointed; while the apical joint is nearly as long as all the other joints combined, enlarges gradually from base to apex, so as to be fully two or three times as large at the apical as at the distal extremity, and bears a pair of exceedingly long and slender, apparently simple, very slightly curved claws, nearly half as long as the apical joint itself. In other respects it closely resembles the genus OedUmychis Latr. 19. Oryctoscirtetes protogasum.- A single specimen, pretty well preserved, and exhibiting the dorsal surface, was obtained by the United States Geological Survey of the Territories near Castello's ranch, South Park, Colorado. The head is pretty large, nearly as broad as the prothorax, the eyes moderately large, apparently circular, with large facets, their average diameter being nearly .02m, a. The prothorax is broad, with well rounded, somewhat convex sides and front lateral angles, the anterior margin considerably concave; the* posterior lateral angles are rectangular, and there is apparently a median furrow on the posterior haff, although the appearance may be due to the crushing of the fossil. The surface of the prothorax, and also of the elytra, is very delicately granulate; the elytra are also furnished very indistinctly with several ( five or six!) longitudinal ridges, straight and equidistant. The, fore femora are swollen as well as the hind pair, but the middle femora cannot be seen. Both middle and hind tarsi are fully four- fifths as long as their tibiae. Length, 5nm; breadth, 2.25miB; width of head, 1.25mm; of prothorax, 1.8-; length of same, .92, n, n: of elytra, 3mm; of middle tibiae, 1.34mm; of middle tarsi, 1.12ara; of middle claws, . IS" 00; of hind femora, 1.32mm; breadth of same, .48mni; length of hind tibiae, 1.4m,°; width of same, .18";- length of hind tarsi, 1.14mm; of first joint, .32mm; of fourth joint ( excl. claws), .48m, n; of claws, .22mra; breadth of fourth joint at tip, . lmm. 20. Trypodendron impressus.- This species is represented by a single specimen, showing the prothorax and elytra, and was obtained from the Green River Beds in Western Wyoming by Mr. Richardsdn. It is slightly larger than T. retusus ( Le C), but has the prothorax punctured as distinctly as the elytra, and the punctures on the elytra show but a slight tendency to a longitudinal arrangement. The punctures of the prothorax are longitudinally obovate, a very little more frequent than on the elytra, equally distributed throughout; on the elytra they are also equally distributed, but circular, about 0.04mm in diameter, and aver- # age. l" m in distance apart: they have but an obscure longitudinal arrangement into nineteen or twenty rows; and the successive punctures of each row are at about the same average distance apart as those of two contiguous rows. Length of prothorax, 1.28mm; height of same, 1.44ram; length of elytra, -• 8aa; breadth of same, 1.24mm. 21. Sitines grandcevus.- A single specimen, very poorly preserved, was found by Mr. Richardson on Green River, at the crossing of the Union Pacific Railroad. Little can be seen beside a vague outline of the form of the body, with a broken rostrum; the eye is large, obovate, longitudinally disposed, 0.42njm long, and 0.25n" n broad; the elytra are fur- |
