572 GEOLOGICAL SURVEY OF THE TEEEITORIES. 



siz); British Columbia, QuesnelLake; Truckee, Sierra Nevada (Crotch) ; 

 Louisiana (Pfeiffer). 



The specimens are dry or preserved in alcohol. T. angusticoUis is a 

 real western species. I saw only one specimen from Nevada, collected 

 on the western border of the State. An imago from Louisiana, collected 

 by Mrs. Pfeiffer, is preserved in the museum at Vienna, Austria. So 

 far as known, this species is not yet found in Texas or Mexico. Messrs. 

 A. Agassiz and G. E. Crotch observed this species living beneath the 

 bark of pine-trees. 



The winged imagos differ in color, the typical specimens being rufous, 

 though some of them are darker. The single male from Nevada is 

 smaller and the wings not as broad, (one-fortieth inch), and throughout 

 much darker; but among a number of alcoholic specimens from San Diego 

 and Semialunoo there are some nearly as dark; and, moreover, it is 

 not impossible that the Nevada specimen was darkened by carbolic acid 

 in the collecting-bottle. The discovery of the soldiers and of the other 

 stages is very important. T. occidentis, formerly supposed to belong as 

 soldiers to T. angusticoUis, is now to be considered as a different species, 

 the imago of which is still unknown. 



T. occidentis, Hagen, Synop., 3, 2. 



Soldier. — Very stout, rufous ; abdomen yellow ; head large, nearly as 

 broad as long ; convex above, rounded laterally, depressed anteriorly, 

 the anterior angles prominent, jointed, dark-brown ; antennae 19-jointed, 

 pale, the first and third joint longer, dark brown ; labrum ovoid, yellow ; 

 eyes present, black, oval ; mandibles shorter than the head, black, stout, 

 curved, the left one with a double tooth before the tip. Prothorax 

 broader than the head, large, flat, cordiform, the anterior margin deeply 

 notched ; mesothorax large, broad, with a short, flat, triangular, alar lobe ; 

 metathorax shorter and narrower, the alar cover smaller. Abdomen 

 large, long, ovoid ; appendages very short, conical, 2-joiuted; last ventral 

 segment with two small spines placed near together ; feet stout, brown ; 

 femora rufous. 



Length, 19 millimeters. 



Larva. — Pale-yellow; head brighter yellow, rounded, flat above ; anten- 

 na^- pale, about 22-jointed ; eyes present, black, well defined. Prothorax 

 as broad as the head, transverse ; angles rounded, the hind ones more 

 obtuse ; mesothorax of the same size, flattened, transverse, a little 

 broader ; on each side a triangular, depressed alar lobe nearly as long as 

 the metathorax ; the latter similar but larger ; the abdomen broader, 

 thick, ovoid ; the appendages and spines similar to those of the soldier. 

 Feet less stout, yellow. 



Length, 14 millimeters. 



Habitat. — California : Cape San Lucas (Xanthus de Vesey). The 

 type of Walker from the west coast of Central America. The described 

 specimens are preserved in alcohol. The descrijDtious of the previous 

 stages of T. angusticoUis and T. occidentis prove the difference of the 

 two species. The soldier of T. occidentis differs by the rounded 

 shorter head ; the two-toothed mandibles ; the prothorax very large, 

 broader than the head, and nearly bilobate; the alar lobes large, flat, 

 horizontal; the appendages very short, two-jointed ; the eyes black, well 

 developed. The larva differs by the alar lobes large, directed down- 

 ward ; the prothorax transversely oblong ; the abdomen thick, ovoid ; 

 the appendages similar to those of the soldier ; the eyes black, well 

 developed. 



The imago is still unknown ; I. suppose they belong to the genus Ter- 



