THE CANADIAN ENTOMOLOGIST. 257 



NOTES ON THE GENUS OSMIA. 



BY E. S. G. TITUS, UREANA, ILLINOIS. 



The maxillary palpi of Osmia (sens, lat.) are given by most authors as 

 four-jointed. I have examined the maxillary palpi of sixteen species in 

 this group, and find in every instance that these palpi are five-jointed. 

 The first joint is usually small, sometimes globular in shape, and visible 

 with a hand-lens only under very favorable conditions. The following 

 species were examined : From the coll. of the State Agr'l College of 

 Colorado — O. armaticeps, Cr. ; Coloradensis, Cr. ; dubia, Cr. ; fulgida, 

 Cr. ; Integra, Cr. ; lignaria. Say, and mandibular is, Cr., all from 

 Colorado. 



Fig. 9. 



From the U. S. Nat. Museum— a abject a, Cr. (Calif.) ; albiventris, 

 Cr. (Can.) ; armaticeps, Cr. (Colo.); Californica, Cr. (Calif.); chalybea 

 (Fla.); cobaltina, Cr. (La.); densa, Cr. (V. I.) ; distincta, Cr. (Penn.) ; 

 'dubia, Cr. (Colo.) ; lignaria, Say (Kans., Ga.) ; integra, Cr. (Colo.), and 

 marginipennis, Cr. (La.). From the collection of Mr. Wm. H. Ashmead 

 — O. Californica, Cr. (Wash.) ; chalybea (Wash.) ; cobaltina, Cr. (La.) ; 

 distincta, Cr. (Wis.). From Ohio University— O. chalybea, Sm., and 

 lignaria, Say; also a few other specimens from various places — O. 

 chalybea, Sm. (N. ].); albiventris, Cr. (Penn.) • lignaria, Say (Wis., 

 Penn.), and megacephalus, Cr. (Penn ). 



I wrote to Prof. Cockerell regarding these facts, and under date of 

 May 20, ioor, he replies: " / hasten to assure you that Osmia has 

 ^-jointed maxillary palpi. * * * To make the thing doubly sure, my 

 wife and I just tiew examined the maxillary palpi of thefolloroiug species, 

 and they are all S-jointed : 0. lignaria, O. cornuta (Europe), O. pheuax, 

 O. albiventris, O. Kincaidii, O. brcvis, O. calla, O. nanula." 



