758 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



the character of the basal cells, and other parts of the base of the wing, 

 the relation of the auxiliary to the first longitudinal vein, and to map 

 unquestionably the whole course of the fourth longitudinal vein, we shall 

 probably be able to arrive at very precise conclusions. 



In addition to the features above mentioned, it may be added that 

 the thorax is subquadrate, scarcely longer than broad, furnished with 

 distant, long, ciirving bristles disposed in rows, but in no individual 

 well enough preserved to give further details of distribution. The 

 abdomen is composed of five visible, subequal joints; its mass compact, 

 scarcely constricted at the base, regularly and pretty strongly arched 

 on a side view, tapering rapidly on the apical half to a bluntly rounded 

 apex, the surface abundantly clothed with rather delicate spinous hairs, 

 those at the posterior edge of the segments longer, and forming a regu- 

 lar transverse row. The metatarsus of the middle leg is proportionally 

 longer than in the others, where it is about half as long as the other 

 joints combined. 



Measurement of average individuals: — Length of body as curved 

 4.25'»'^, of head 0.65™°', of thorax 1.7'°'", of abdomen 2.2'°'° ; breadth of 

 head 0.85°'°', of thorax 1.25°'°', of abdomen 1.4°'°'; length of flagellum of 

 antennae 0.16°"°, of style 0.19°'°', of wing 3.4'°°^?; breadth of same 1.2°'°'; 

 length of femora 0.75°'°', of tibise 0.95°'°', of fore tarsi O.So™™, of middle 

 tarsi 1.5°'°', of hind tarsi 1.6°'°', of fore metatarsi 0.4'°°', of middle meta- 

 tarsi 0.64°'°', of hind metatarsi 0.48°'°'; breadth of femora 0.28°'°', of 

 tibiai 0.12°'°', of metatarsus 0.08°"°, of tip of tarsi 0.05™°'; length of claws 

 O.OO™™. 



Sciomyza ? disjecta. — A second species, ai)parently of the same genus 

 as the last mentioned, but smaller, is found in considerable numbers in 

 the same bed, although in far less abundance than the last, a dozen 

 specimens having been found by Mr. Eichardson, Mr. Bowditch, and 

 myself. The wings appear to be proportionally shorter than in the last 

 species, with a rather broader space between the veins in the upper half 

 of the wing, indicating perhaps a broader wing. The legs are slen- 

 derer, the disparity in the stoutness of the tibiae and tarsi is not so 

 great, and the tarsi are proportionally shorter ; the legs are also as 

 densely, though less coarsely, spined, and a similar delicacy is observa- 

 ble in the hairiness of the body. All the specimens are preserved on a 

 side view, and the last species are in a like fragmentary condition. 



Length of body of an average individual 3.2°'°', of head O.SS™™, of 

 thorax 1.2°'°', of abdomen 1.8™°', of wing 2.4™™?, of hind femora 1.2°'™, 

 of hind tibise 1.4™™, of middle and hind tarsi 1™™. 



OOLEOPTERA. 



CAEABID^. 



Cyclirus testeus, — A single specimen (No. 4059) with its broken reverse 

 (Ko. 4100) shows a pair of elytra slightly misplaced. They appear to 

 represent a small species of Cyclirus allied to C. angusticolUs Fisch., but 



