1896.] NATURAL SCIENCES OF PHILADELPHIA. 71 



cell has the poststigmatal portion appreciably longer than the sub- 

 stiofmatal, the third discoidal is distinct. 



From P. pedidis, it differs thus : 



(1). Larger, niesothorax dull, granulated, markings of face and 

 abdomen yellowish, ..... z=zajffinis 9 . 



(2). Smaller, niesothorax smooth, very shiny, markings of face 

 and abdomen white, ..... =pectidis 9 • 



In its face-markings, dull mesothorax and dark nervures P. 

 <(ffinis 9 agrees precisely with octomaculata 9 , but it differs thus : 



(1). Larger, markings of abdomen chrome-yellow, wings tinged 

 smoky or yellowish, .... =octomaculata 9 • 



(2). Smaller, markings of abdomen creamy or yellowish-white, 

 wings clear or nearly so, . . . . =^affinis 9 • 



I have not seen the $ of affinis. Mr. Fox kindly sends me a 

 sketch of the face-markings, showing the face all yellow below the 

 level of the antennse, the yellow extending above in the median line 

 as a small rounded projection, and at the sides obliquely from the 

 antennal sockets to the orbital margin, where it ends at an angle 

 of about 50". Thus the face-markings of affinis $ differ at once 

 from those of octomaculata $ , which has the yellow confined to 

 clypeus and sides of face, except a couple of small spots or streaks 

 in the place of the supraclypeal mark. 



26. Perdita sexmaculataCkll., Proc. Phila. Acad., 1895, p. 12. 9 (Hab,, Santa Fe, 



N. M.). 



The unique type was taken on July 25th ; it could hardly have been 

 on Solidago, which would not, I think, be in flower at Santa Fe at 

 that time. I have a note in my diary that on Aug. 2, 1895, Solid- 

 ago canadensis was only beginning to flower, and was visited by a 

 few Halictus. The form found on Solidago in Colorado represents 

 a variety, as follows : 



Var. punctata $ . 



Length about 6 mm. ; abdomen with only 4 pale dots, on segments 

 3 and 4. As it is possible that this will prove to be a distinct 

 species when a good series is collected, the following additional 

 particulars are oflered : 



Head and thorax greenish-black, metathorax blue-black. Man- 

 dibles yellowish with rufous tips. Face and mesothorax very little 

 hairy. Vertex and mesothorax granular, quite distinctly dark 

 greenish. Clypeus black, minutely granular, sparsely and irregu- 

 larly punctate. Scutellum with the granulations becoming obsolete 



