446 GEOLOGICAL SURVEY OF THE TERRITORIES. 



FA3IILY II.— ACEIDIDJB. 



Sub-family Aceidini^. 



First group. — TruxalinL 



Opomola, Erichs. 



0. hrachyptera,^ Scudd., (Bost. Jour. Nat. Hist., YII, 454.) 

 Thos., (Proc. Phil. Acad. Nat. Sci., 1871.) 



As Mr. Scudder at tlie time he described this species had but a 

 single male specimen, I have concluded to give a full description of 

 the unique female specimen I obtained in Wj'oming Territory". 



Female. — Vertex carinated; elytra narrow, reaching the tip of the 

 second abdominal segment. Antennce broad, ensiform. Pale orange- 

 brown, with dusky points. 



Occiput convex, straight, not ascending, with a slight, shallow, longi- 

 tudinal depression each side, leaving a low, rounded, median ridge. Ver- 

 tex triangular, margins turned up, Avitha strong median carina, the three 

 meeting in front in a blunt point; length, in advance of the eyes, equal 

 to about one-third of the entire length of the head. The face tricarinate, 

 or rather quadricarinate, as the frontal ridge is so deeply sulcate that it 

 forms two distinct carinte, which meet at the vertex; all somewhat 

 divergent, and reaching the clypeus. Eyes oblong-ovate. Autenuie 

 scarcely as long as the head and thorax, ensiform, flattened, and slightly 

 triquetrous. Prouotum about as long as the head, tricarinate; sides 

 parallel ; onlj^ the posterior transverse impression distinct on the disk, 

 situate a little behind the middle. Elytra lanceolate, narrow, reaching 

 the tip of tbe second abdominal segment. Wings narrow, minute, about 

 half as long as the elytra. Abdomen long, slender, and somewhat cylin- 

 drical, slightly carinated. The four anterior legs slender; i)osterior 

 femora, slender, straight, not as long as the abdomen ; i^osterior tibiae 

 slender, nearly cylindrical, somewhat hairy at the apex. Prosternal 

 point is only a blunt tubercle. 



Color, (dried, after long immersion iu alcohol.) — Pale orange-brown, 

 without distinct spots or markings, but with numerous minute dusky 

 points. The antenna? are purplish brown ; the vertex, legs, and abdo- 

 men tinged with the same color. Spines of the posterior tibia?, abdom- 

 inal appendages, and tarsal claws tipped with black. When living, 

 the only specimen I have seen in the i)erfect state, was of a uniform 

 grayish-brown ; length, 1.5 inches. 



My specimen was obtained near the ruins of old Fort Casper, on the 

 North Platte Eiver, Wyoming Territory, August 22. I have some 

 larv?e and pup?s obtained in Cache Valley, Utah, w^hich iDOSsibly belong 

 to this species. 



0. Wi/omingenslSj Thos. 



Sjm., Mesops Wyomingensis, (Proc. Phil. Acad. Nat. Sci., 1871.) 



Small, slender, and cylindrical; elytra reaching the fifth abdominal 

 segment; abdomen of the male terminating in an acute prolongation. 

 Pale green, sometimes varied with reddish, immaculate. 



^ This specific Dame is twice used; the Acridhim (Pyrgomorjyha) hraclujpiera, 

 Haaii, (Yerz. Nat. Gcsch. Ned. Ind. Bez. lus., 150,) having been referred by Walker to 

 O])omo'la, becomes 0. hrachyptem, but Mr. Scudder's species received the name first, 

 hence must stand, and that of Walker changed. (See Walk. Cat. Dcrmop. Salt., Ill, 

 514.) 



