BRUES: PARASITIC HYMENOPTERA. 31 



cell are considerably longer, and the discoidal smaller and more elon- 

 gate. This cell appears to be smaller than in any living species of 

 Aulacus or allied genera with which I am familiar and suggests a 

 relationship to Foenus (Gasteruption) in which this cell is very small. 

 It would appear therefore that the present form may have been related 

 to some of the transition forms between Foenus and the more general- 

 ized Evaniidae. 



ICHNEUMONIDAE. 



ICHNEUMONIN AE . 



Only one species, a Trogus, is contained in the collections from 

 Florissant. Heer ('67) has described as Ichneumonites fusiformis a 

 species which he thought probably a Trogus, but which from its sessile 

 abdomen and long ovipositor is evidently a pimpline. 



Trogus vetus, sp. nov. (Fig. 21.) 



Probably a female. Length about 15 mm. Black, the abdomen pale 

 brown with transverse black bands. Wings hyaline. Rather stout, head 

 large and broadly transverse; antennae preserved only at the extreme base 

 where they are rather slender. Face and front black, with a central pale 

 yellowish brown spot above the insertion of the antennae. Mesonotum 

 smooth or very finely shagreened; scutellum convexly elevated, with a 



Fig. 21. — Trogus vetus, sp. nov. Type. 



depression at its base that is margined by a raised line on each side which does 

 not extend to the raised portion. Metanotum partially areolated, there being 

 a single large lateral area on each side separated from the single median one . 

 Abdominal petiole black, the postpetiole margined narrowly bshind with dull 

 yellow or pale brown. Postpetiole finely punctate, the extreme tip rugose; 

 second segment pale brown, with a transverse ^quadrangular^black spot medi- 

 ally; third with a much smaller, more nearly round dark spot; fourth with a 



