GEOLOGICAL SURVEY OF THE TERRITORIES. 279 



genus between them. Before a true natural arrangement can be ob- 

 tained the species of these genera and of the heterogeneous Oedipoda 

 will have to be thrown together and then separated into groups by other 

 characters. 



T.pseudo-nietamis, Thos. Syn., T.pseudo- nietanus, Thos. (Proc. Acad. 

 Nat. Sci., Phila., 1870, p. 82.) — Male: Size and appearance much like T. 

 nietanus, (Sauss.,) from which it differs only as follows : The facial costa is 

 slightly broader and less excavated below' the ocellus ; the occiput and 

 pronotura less rugose; the antennas nearer cylindrical. The color is 

 darker, the sides being deep-black throughout to the extremity of the 

 elytra; the posterior part of the occiput and dorsum of the pronotuni 

 an ashy yellow, the front lobe and lateral margins of the pronotum. 

 dotted with black ; the upper edge of each posterior femur has two 

 yellow spots, the one next the base the larger ; the entire under surface 

 a shining black; wings, as in nietanus ; base rosaceous; posterior mar- 

 gin broadly margined with black, and a facia of the same running along 

 the anterior sub-margin nearly to the base. 



Dimensions. Male : Length, 1 inch ; to tip of elytra, 1.25 inch ; femur, 

 .07 inch. ; tibia, .53 inch. 



Habitat: Found near Oanon City, Colorado, close to the mountains 

 in a canon; also near Fort Fetterman, Wyoming. 1 have not seen the 

 female. This may possibly be a variety of T. nietanus, but from the 

 permanent difference in the color of the pronotum, and from the fact 

 that it was found at but one point in Colorado, and over a very limited 

 territory in Wyoming, while the other was found more generally distrib- 

 uted on the Plains, I conclude it is a different species. 



[Note. — While passing from Fort Fetterman to Eed Buttes, in Wyom- 

 ing, we encountered a vast swarm of Caloptenus spretus, not Hying but 

 on the ground pairing. I noticed here, as I had under similar circum- 

 stances before, that where these were very numerous, few specimens of 

 any other species were to be found. In this case almost the only species 

 to be seen were T. nietanus and Oe. trifasciata, whereas but a few miles 

 back other species could be found in abundance.] 



STENOBOTHRUS, (FISCHER.) 



a. Antennse filiform or sub-filiform. 



&. Lateral foveolse obsolete. 



[Note. — It was with some hesitancy that I concluded to describe 

 any of the species which appear to belong to this genus. Although 

 Fischer is generally very careful and exact, the characters of this 

 genus, as given by him, show the difficulty he has fallen into by cling- 

 ing too closely to variations in a given part. The consequence is that 

 this genus has become the receptacle for a number of species varying 

 widely from the type. In fact, we may truly say that the distinguishing 

 character (if his italics are to be relied upon) is the exception instead of 

 the rule. Finding that neither Scudder nor Saussure had allowed them- 

 selves to be trammeled by this character, I have concluded to follow 

 them. The subdivisions given above are after Saussure, the latter 

 being in direct opposition to the leading character before alluded to. 

 But, notwithstanding these strictures, I admit there is a marked group 

 for which Fischer evidently intended this genus, the similarity being 

 easily detected by the eye.] 



St. obionus,iiov. sp. — Female: Head somewhat narrow, face sub-verti- 

 cal; vertex slightly deflexed, rounded in front, margins elevated, a slight 

 median line; frontal costa obtuse, convex above, with a very slight 

 depression at the ocellus; pronotum sub-truncate in front, posterior 



