750 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



O. (Ceratosmia) lignaria Say. 



Has been captured in New Haven, 25 May, 1904 (B. H. W.), 

 4 May, 1904 (H. L. v.), and in Branford, 8, 11, 26, 29 May, 1905 

 (H. W. W.), visiting apple and quince blossoms. 

 °0. (Centrosmia) bucephala Cresson. O. latitarsis Cresson. 



O. (Osmia) pumila Cresson. 



New Haven, 17 June, 4 July, 1905 (H. L. V.). Visits flowers 

 of the red raspberry. 



O. (O.) major Robertson. 



New Haven, 9 June, 1905 (B. H. W.) ; Branford, 3 July, 1906, 

 (H. W. W.), visiting floWers of honeysuckle {Lonicera fragran- 

 tissima). 



O. (O.) simillima Smith. 



*0. (O.) atriventris Cresson. 

 Farmington ( ?) ; Berlin, 30 June, 1905 (W. E. B.). 



O. (O.) rustica Cresson. 



Branford, 29 May, 1905 (H. W. W.), on lilac blossoms. 



°0. (O.) vicina Cresson. 



*0. (O.) purpurea Cresson. \ 

 Farmington (?). 



*0. (Nothosmia) distincta Cresson. Howard, Insect Book, 

 PI. iii, Fig. 13. 



Farmington (?). 



°0. (Monilosmia) canadensis var. cognata Cresson. Howard, 

 Insect Book, PI. iii, Fig. 18. 



*0. (Diceratosmia) conjuncta Cresson. O. quadridentata, O. 

 cressoni. 



*0. (Leucosmia) albiventris Cres$on. 



Andronicus Cresson. 

 To this group belong black, slender species. 



Key to Species. 



Females. 

 I. Mandibles tridentate; clypeus coarsely punctate; ventral 



scopa whitish 2 



Mandibles quadridentate; clypeus finely punctate; ventral 

 scopa yellowish cylindricus 



