220 The Ottawa Naturalist. [January 



26. Crossocerus minimus, Pack. Our smallest species of the sub- 



family. One female and four males, taketi in June. Fox in his 

 monotfraph of the crabronids says that he had not seen the male. It 

 differs little from the female except in beingf slig'litly smaller and in 

 having a little more 3'ellow on the legs. 



27. Cuphopterus maculipennis, Smith. This is a not uncommon 



species, prettily marked with yellow, and easily recognized when 

 living, by the maculate wings, the spots upon which fade out very 

 much in cabinet specimens ; 4 females, 5 males. 



Subfamily IV. — Rhopalince. 



28. Rhopalum pedicellatum. Pack. The insects in this subfamily 



are rather small, and are easily recognized by the petiolate abdomen. 

 This species is common and forms its nests in the stems of elder and 

 raspberry; 15 females, 10 males. 



29. Rhopalum rufigast.er, Pack. Only one female of this small ( 



species, with abdomen partly red. 



Family XVII. — Pemphredonidae. 



Subfamily I, — Pempredonince. 



30. Stigmus fraternus, Say. A small species, abundant ; 8 female 



5 males. 



31. C e m o n u s i n o r n a t u s, Say. A common form ; 12 females, '_ 



males. 



32. Pemphredon concolor, Say. V^ery similar in appearance b 1 1 



larger and not so common ; 2 females, 2 males. 



33. Passaloecus m a nd i bu 1 a r i s. Cress. The triangularly produce ( 



labrum and short petiole distinguishes this genus from C e m o n u 

 and Pemphredon. Three females. 



34. Passaloecus annulatus. Say. Smaller, with paler legs ; 2 



females, 2 males. 



35. D i o d o n t u s a m e r i c a n u s , Pack. One female from Dr. Fletcher. 



Subfamily II. — Psenhice. 



36. M i m e s a b o r e a 1 i s, Smith, Second segment ot abdomen red ; 



females. 



37. M i m e s a n i g e r. Pack. All black ; 2 females, i male. The species 



much resembles in general appearance the smaller individuals of 

 Pemphredon concolor, but is more slender and has the 

 thorax more polished. 



38. P s e n t r i s u 1 c u s, Fox. Taken near Hull in Jul}' ; i female, i mal 



