54 bulletin: museum of comparative zoology. 



Type. — 'So. 2025, Mus. Comp. Zobl. Florissant, Col. (No. 6013, S. II. 

 Scudder Coll.). The first abdoniiiial segment having a distinct though short 

 (less than 1 mm. long) petiole is suggestive of Sphecidae, but the insect does 

 not otherwise agree with that group. The first abdominal segment really 

 recalls the winged Mutillidae allied to Photopsis, as much as anything ; but 

 the ventral surface of the abdomen is perfectly straight (or rather, gently con- 

 vex), without the least sign of a depression between the first and second seg- 

 ments. The well-developed stigma is suggestive of Ceropales, but the venation 

 differs from that of any modern genus known to me. I cannot see the third 

 submarginal cell distinctly, but it appears to have been present. The dark 

 spot below the stigma is still slightly iridescent. 



VBSPIDAE. 



Palaeovespa, gen. nov. 



With the general form of Vespa, the thorax broadly rounded, and the abdomen 

 sessile and broad at base ; the first segment of transverse form, yet by no means 

 so broad as in true Vespa. Venation more like Polistes, the marginal cell being 

 pointed, the apex of first discoidal oblique, and the recurrent nervures joining the 

 seconds, m. far apart, not both entering the basal half of the cell, as in Vespa. 

 The b. n. joins the subcostal nervure nearer to the stigma than is usual in Vespa, 

 but not at its base, as in Polistes. It is impossible to see whether the hind wings 

 have an anal lobe or not. This is a very interesting genus, having the appearance 

 rather of Vespa (it would never occur to any one to refer the specimens to Polistes), 

 but retaining the apparently more primitive venation of Polistes, or a close approx- 

 imation to it. P.Jiorissuntia, the largest species, is taken as the type, but the char- 

 acters of the genus are not all ascertainable from the single specimen of that insect. 



Palaeovespa florissantia, sp. nov. 



Very large and robust; length to beyond middle of fifth abdominal segment, 

 26 mm. ; length from base of abdomen to apex of fourth segment, 14 mm. ; thorax 

 narrow for the size of the insect, its width between wings about 7 mm. ; breadth of 

 abdominal segments in mm. (1) 6^, (2) 8^, (3) 8f ; color dark, evidently black in 

 life, with the hind margins of the abdominal segments broadly but suffusedly pal- 

 lid; no distinct abdominal markings; wings apparently reddish. The venation is 

 obscure, but the wings appear to be folded, and the very long first discoidal cell 

 of tlie Vespidae is plainly visible, its length about 10 mm., while its breadth is only 

 about I| ; the lower part of the basal nervure is about 6 mm. long, and tlie first 

 s. m. on cubital nervure is about 3f ; the second s. m., very faintly indicated, 

 appears triangular, the first t. c. oblique, its upper end most distad, the acute 

 angles formed being of about 45° ; the apex of the first discoidal, between the first 

 t. c. and the insertion of the first r. n., is obliquely truncate, — considerably more 

 obliquely than in a modern Vespa examined. 



Type. So. 2026, Mus. Comp. Zobl. Florissant, Col. (No. 11,741, S. H. 

 Scudder Coll.). This is the largest by far of the Florissant Hymenoptera seen 



