353 



Revision of the FOSSORIAL HYMENOITERA of North America. 



I. Crabronid^e and Nyssonidje. 



BY A. S. PACKARD, Jr., M. D. 



[Continued from page 115.] 



THYREOPTJS, St. Fargeau et Brulle. 



Thyreopus, St. Fargeau et Brulle. Ann. Ent. Soc. France iii, 1837. 



Head transversely oblong, being one-half as long as it is broad, 

 wider than the thorax ; in front deeply furrowed, being depressed from 

 behind the eyes, sloping rather rapidly to the broad, deep, antennal 

 groove. Ocelli arranged in an equilateral triangle on the elevated ver- 

 tex ; front more broadly triangular than usual. % antennae thick and 

 short, with 13 joints, 2nd much ciliated, 4 — 13 very broad and flatten- 

 ed ; under side of 4th — 6th joints with short curved pencils of silvery 

 pubescence; within dentate, terminal joint cylindrical. In the more 

 aberrant species the % antennas are only slightly flattened or entirely 

 simple. Iu the $ the antennae are simple, cylindrical, slender, fili- 

 form, not thickened towards the tip. Clypeus one-half as long as broad, 

 convex in front, edge smooth, base square, with a thin median ridge, 

 most prominent at the base ; covered closely with a dense silvery pu- 

 bescence. In $ the joints of the maxillary palpi are broader than in 

 % , 3rd and 4th joints of nearly the same length ; 5th much swollen at 

 tip; 6th long, cylindrical. Labial palpi much thicker than in % , 2 — 

 3 joints broadly triangular. Lingua nearly obsolete in S and often in $ . 

 In one 9 it reaches a little beyond the mandibles, is compressed and 

 deeply divided, the lobes being very narrow. Mandibles of even 

 width, the teeth unequal, rounded, truncate. Thorax sub-globose, pro- 

 thorax angulated on the sides, with a lateral tubercle, more acute in 

 % . Meso-scuturu behind curving gradually around to the seutellum 

 which is small and sublunate. Propodeum much as usual, but narrow- 

 ed behind. 



Legs with broad triangular coxae, beneath provided with a large, 

 acute tubercle, trochanters longer and narrower than the coxae; fore 

 femora broad; fore tibia armed externally with a broad, triangular, 

 shield-like expansion, often much longer than the length of the joint, 

 sometimes lobed, the end acute or obtuse. The femora in T. latipes 

 has a much smaller, though similar expansion, with a long, slender 

 hook at the base of the opposite side. First joint of the tarsus short, 

 broadly flattened, produced bluntly at the tip, remaining joints very 

 short and broad, the terminal one produced laterally into a long vex- 



PROCEEDINGS ENT. SOC. PHILAD. FEBRUARY, 1867. 



