152 PROCEEDINGS OP THE ACADEMY OF 



the posterior tibise, abdominal appendages, and tarsal claws tipped 

 with black. 



"When living, the only specimen I have seen appeared to be of a 

 uniform grayish-brown. Length 1,5 inches. 



My unique specimen was caught near the ruins of Fort Casper, 

 on the North Platte, Wj'omiug Territory, August, 1870. Found 

 in the tall grass on the river bottom. 



Mesops wyomingensis, Thos. nov. sp. 



Small, slender, cylindrical ; elytra reaching the fifth abdominal 

 segment; abdomen of the male terminating in a pointed process. 

 Pale green, sometimes varied with red, immaculate. 



Female. Occiput convex, slightly bowed up in the middle ; a 

 very slight median ridge can be discerned which reaches a little 

 in front of the eyes, where it suddenly terminates in a semicircular 

 depression, which separates it from the vertex. The vertex is flat 

 above, conical, margin not turned up, triangular, advanced con- 

 siderably in front of the eyes; a shallow foveola ma}' be distin- 

 guished under each lateral margin ; the circular depression which 

 divides it from the occipital ridge, sweeps round from the upper 

 canthus of one eye to that of the other. The face quadricarinate 

 — the frontal ridge being so deeply sulcate as to appear like two 

 distinct carinse, all prominent, sharp, divergent below, and reach- 

 ing the cross suture ; the sides of the frontal ridge approach each 

 other just below the ocellus, and on each side, directly opposite 

 this constriction, there is a short transverse indentation (this 

 appears to be constant). Eyes oblong-ovate, somewhat promi- 

 nent, situated near the antennre. Antennas flattened, broad, and 

 somewhat prismatic. Pronotum about as long as the head, nearly 

 cylindrical, not carinated, though a faint median line is some- 

 times visible. Elytra narrow, sharply rounded at the apex, 

 reaching to the anterior margin of the fifth segment. Wings 

 nearly the same length. Abdomen elongate, cylindrical, slightly 

 enlarged at the apex ; appendages short, the upper ones nearly 

 covered b}^ the super-anal plate ; the cerci are mere points. The 

 four anterior legs are very short and delicate; posterior femora 

 of moderate length, reaching the tip of the fifth segment, slender 

 and deeply channelled below ; posterior tibiae about the same 

 length as femora, very slender, cylindrical, furnished with delicate 

 spines about two-thirds their length; tarsi somewhat elongate, 



[July 25, 



