1897.] NATURAL SCIENCES OF PHILADELPHIA. 355 



Hab. — Mesilla Valley, close to the Agricultural College, on flow- 

 ers of Baileya multiradiata, May 21, 1897, both sexes taken. The 

 $ I have described previously ; the species is quite remarkable for 

 having more light color on the face in the 9 than in the $ . The 

 9 of callicerata closely resembles the $ of albovittata, but differs at 

 once by the color of the antennae, the yellow anterior tibia?, etc.; 

 the face-marks of the two are almost exactly alike. 



Perdita larrese Ckll. var. modesta, n. var. 



$ . Like the type, but head not nearly so large, being only about 

 as big as the thorax. 



Hab. — Mesilla Valley, close to the Agricultural College, May 21, 

 1897, two at Larrea. 



Centris morsei n. sp. 



$. Length 21 mm., stoutly built, black, with pale ochraceous 

 pubescence, very dense on thorax. Clypeus bright lemon-yellow, 

 with anterior margin rufous ; labrum yellow ; mandibles dark 

 rufous with black tips ; scape without any yellow ; eyes sage-green, 

 suffused with crimson at the extreme base ; facial quadrangle longer 

 than broad, but of the broad type; wings dusky hyaline; tegulse 

 cream-color ; first abdominal segment with abundant pale pubes- 

 cence ; remaining dorsal segments uniformly and completely deli- 

 cately pruinose-pubescent, producing a grayish appearance; apical 

 margins of segments colorless or rather whitish-hyaline, extreme 

 base of third segment, and of second segment at sides ferruginous, 

 this ferruginous portion being overlapped by the white margin of 

 the segment before. Venter with dense yellowish-white hairs ; apex 

 with pale shining hairs, genitalia ferruginous. 



Compared with the $ of C. cazsalpinice, which it most resembles, 

 C. morsei is considerably larger, the thoracic pubescence inclines 

 more to mouse color, and the pruinose-pubescent abdomen with its 

 two more or less defined reddish bands is very different. In morsei 

 the hind tarsi have a black brush on the inner side, but the abund- 

 ant long pubescence is all ochraceous, not at all fuscous or blackish. 

 The long hairs of the anterior tarsi are blackish, though shining, 

 and appearing golden in certain lights. 



Hab. — Mesilla, New Mexico, bed of the Rio Grande, June 28, 

 1897. Taken by Mr. A. P. Morse. 



