466 AMERICAN HYMENOPTERA. 



squama at most not very strongly bilobed, the inner lobe 

 being pointed and the outer one very broadly rounded. 

 Sagitta of characteristic form, with head and shaft rather 

 strongly demarcated from each other by the incurving or 

 notching of the outer margin at the base of the former ; 

 shaft without a very prominent tooth-like projection on its 

 ventral side. 



Psitliyrus ashtoui (Cress.) D. T. 

 Apathus ashtoni Cresson, Proc. Ent. Soc. Phila., Ill, 1864, p. 42, n. 7, 

 9. 

 *' Packard, Proc. Essex Inst., IV, 1864, p. 118, 9 ; T. 3, 



F. 1. 

 " Packard, Amer. Natural., II, 1868, p. 203, T. 5, F. 1. 

 " " Packard, Our Common Insects, T. 1, F. 1. 



" Cresson, Trans. Amer. Ent. Soc, VII, 1879, p. 230 

 (Catal.). 

 Bowles, Ann. Rep't Ent. Soc. Ont., 1880, p. 33. 

 Provancher, Natural. Canad., XIII, 1882, p. 268, n. 2, 



9. 

 Provancher, Faun. Ent. Can. Hym., 1883, p. 736, n. 2, 



9. 

 Cresson, Syn. Hym. No. Amer., 1887, p. 307 (Catal.). 

 Packard, Guide to Study of Insects, p. 131, T. 3, F. 1, 



9. 

 Provancher, Addit. Faun. Can. Hym., 1888, p. 342, 

 9. 

 Psithyrus ashtoni T>a\\a. Torre, Cat. Hym., X, 1896, p. 565 (Catal.). 

 ? Bombus ashtoni Harvey and Knight, Psyche, VIII, 1897, p. 79. 

 Psithyrus variabilis Howard, Insect Book, 1904, Plate II, fig. 35. 



ashtoni l^o\&\\, Ent. News, XVIII, May, 1907, p. 199. 

 .? " latitarsus Titus, Biol. Surv. Mich., Ecology of Isle Royale, 

 Lake Superior, 1908, p. 317. 

 " consultus Fletcher and Gibson, Can. Ent. Rec. (Ann. Rep't 

 Ent. Soc. Ont.), 1908, p. Ill (pars). 



Types. — The females described by Cresson are in the col- 

 lection of the American Entomological Society. The males, 

 on which Lovell based his short description of that sex, are 

 probably in his private collection. 



Female. — Head mostly or entirely dark ; dorsum of thorax yellow in 

 front, sometimes yellow and sometimes dark behind ; upper parts of the 

 pleura yellow , but their lower portions dark ; dorsum of abdomen with 

 the fourth segment and the hind corners of the third clothed with yellow 



