Heterogyna and Fossorial Hymejwjotera. 261 



and eyes, somewhat angularly raised, excavated between 

 the projections, and in the middle of the excavation, 

 just above the insertion of the antennae, is a short 

 blunt spine, having its apical margin emarginate ; thorax 

 covered with pale hairs ; mesothorax and scutellum 

 shining, largely and remotely punctured ; metathorax 

 rugose, brow shining and elevated, as in Pemphredori 

 unicolor ; abdomen shining, finely and remotely punctured, 

 with the petiole short and rugose, not nearly so long as 

 the rest of the segment, more or less hairy on the 3rd and 

 following segments, apical segment in the ? very largely 

 punctured, its margins slightly raised ; beneath in the 3' 

 with a thick fringe of hairs across the middle of the 

 3rd, 4th, and 5th segments ; tibiae simple, without lateral 

 spines ; femora hairy beneath. 

 Length 6 — 7 mill. 



Hah. — London district ; rare. 



MIMESID^. 



(2) 1. 2nd submargiual cell reeeivinf^ both recurrent ner- 



vures . . . . . . . . . . . . Mimesa. 



(1) 2. 3nd and 8rd submargiual cells each receivicg a 



recurrent nervure . . . . . . . . . . Psen, 



Mimesa, Shuck. (PL VIIL fig. 29). 



Foss. Hymen, p. 228. 



A genus which resembles Pcmphredon, of the last 

 family, very much in form, but differing in having three 

 submargiual cells ; from Psen the arrangement of the 

 recurrent nervures distinguishes it, as shown in the table 

 above. The form of the petiole is the chief specific 

 characteristic among the members of this genus. 



(0) 1. Body red at the base. 



(0) 2. Petiole of the body Hat, widening posteriorly ; ,3rd 



segment of body in 5 entirely black . . . . Shuclcardi. 



(2) 3. Petiole of the body narrow and not widened pos- 



teriorly ; 3rd segment in 5 more or less reel. 

 (5) 4. Mesopleurffi not punctured .. .. .. .. hicolor. 



(4) 5. Mesopleura; strongly punctured .. .. .. cquestris. 



(1) 0. Body entirely black. 



(8) 7. Petiole cariuated, not widening at the apex; carina 



not grooved .. .. .. .. .. .. unicolor. 



(7) 8. Petiole widened at the apex, carina grooved . . Dahlhomi. 



