410 Prof. T. B. A. Cockerell on 



median impressed line of raesothorax longer, extending as far 

 back as the level of the tegulje. 



Hob. Romeroville, April 29, 1 ? , at flowers of wild goose* 

 berry {W. Porter) ; Las Vegas {R. Devine). 



It is possible that this is a distinct species, and it may even 

 prove to belong to 0. montana, Cress., of which only the 

 male has been described. 



Osmt'a [Melanosmia) nigrifi'onSj Cresson, 

 var. suhaustralis^ nov. 



$ . — Smaller, length 10 millini. 



Anterior margin of clypeus with a distinct hut broad and 

 shalloxc emargi nation, from the middle of which proceeds a 

 very fine raised line traversing the whole length of the clypeus, 

 but only visible in a favourable light ; apical tootli of 

 mandibles longer ; mesothorax with a smooth sparsely punc- 

 tured space on the middle of its disk ; sides of face tinged 

 with greenish (dark purple-blue in nigrifrons) ; mesothorax 

 black, with a faint green tinge posteriorly ; wings clearer. 



Hab. Beulah, July 26, 1 ? ( Wilmatte Porter). 



Probably a distinct species. Cresson, when describing 

 nigrifrons^ seems to have confused this insect with it, as he 

 says " clypeus truncate or obtusely eniarginate.^' 



Osmia {Melanosmia) ribifloris, sp. n. 



? . — Length 11 millim. 



Thickly built (breadth of abdomen 4 millim.), dark shining 

 blue, including the legs, and tegulse more or less ; pubescence 

 black ; wings only faintly tinged with brownish, but the 

 upper half of the marginal cell occupied by a dark brown 

 streak ; mandibles very broad, without any patch of rufous 

 hairs, bidentate, the apical tooth quite long, the other small 

 but sharp, nearer to it than to the inner angle; apex of 

 clypeus entire, shining, slightly rounded; punctures of front 

 and mesothorax strong, large, separate ; punctures of abdo- 

 men distinct but not dense ; ventral scopa all black ; spurs 

 black ; joints 2 to 4 of anterior tarsi inversely cordiform. 



Hab. Romeroville, April 29, 1899, 2 ? , at flowers of wild 

 gooseberry ( Wilmatte Porter) ; Las Vegas, 1 ? {R. Devine). 



Allied to 0. Bruneri and cobaltina, but larger and much 

 more darkly coloured. The spurs uf the hind tibiaj are small 

 and not hooked at the tip, tlius resembling those of cobaltina 

 and differing from those of Bruneri. From several super- 

 ficially similar species it is distinguished by the blue legs. 



