86 PROCEEDINGS OF THE ACADEMY OF [1896. 



Mandibles very little curved, yellow, rufescent at ends. Clypeus 

 approximately cocked-hat shaped, the lateral prolongations broad. 

 Face below antennse all lemon-yellow except a notch of the dark 

 color distad of each dog-ear mark, and not quite so large as it. The 

 supraclypeal mark is roundly emarginate above. The clypeus has 

 the usual two dark dots. Along the orbital margins the yellow 

 ascends about half the length of the scape above the level of the an- 

 tennse, and ends in an oblique truncation ; this upward band of yel- 

 low is a little wider than the scape. The cheeks are entirely dark. 

 Mesothorax smooth and shining, though minutely lineolately sculp- 

 tured, nearly black ; mesothorax finely sculptured, very distinctly 

 blue. Pleura all dark. Tubercles yellowish. 



Tegulse pale brown ; wings slightly smoky, nervures and stigma 

 sepia-brown, the latter pale in middle. Marginal cell large, appendi- 

 culate, poststigmatal portion longest; 2d submarginal narroAved less 

 than half to marginal ; 3d discoidal distinct. Transverse cubital 

 nervures more or less broken by hyaline dots. Legs black, all the 

 knees, anterior and middle tibiae in front, and base of hind tibiiB> 

 yellow ; tarsi pale brownish, the anterior ones yellowish. 



Abdomen above piceous, w'ith narrow whitish bands, interrupted 

 in the middle, rather obscurely indicated on disc of 1st segment, and 

 at base of segments 2 and 3. The markings are in the form of nar- 

 row straight stripes, not oblique ones as in some species. Venter 

 dark brown. 



Hah. — Las Cruces, N. M., one specimen on Gutierrezia sarothrce 

 var. microcephala, Sept. 23, 1895. Allied to P. biparticeps, from 

 which it differs at once in the face-markings, the abdomen, etc. 

 From austlni it differs radically in the face-markings. 



Small species found on Bigelovia wrightii, having the abdomen 

 banded. 



47. Perdita nitidella Ckll., Proc. Phila. Acad., 1895, p. 16. (f. (Hab., Las Cruces, 



N. M.). 



On Bigelovia wrightii at Las Cruces, several males on September 

 2d, one 9 on September 11, 1895. The latter is herewith described : 



9 . — Length 5 mm. Face-markings creamy-white. Clypeus white 

 with two black dots, the anterior margin narrowly brown, and traces 

 of the two longitudinal bars in brown. Sides of face with an irregu- 

 larly subtriangular white mark, the upper obliquely truncate end of 

 which is level with the insertion of the autennie. Cheeks quite 



