1896.] NATURAL SCIENCES OF PHILADELPHIA. 55 



5. Perdita interrupta Cr., Tr. Am. Ent. Soc, 1878, p. 70. $ (Hab., California). 



Three specimens were found by Crotch ; we have no information 

 as to exact locality or habits. From one of the types I noted the 

 following : 



• Cheeks unarmed, quite densely (for a Perdita) white pubescent. 

 Face more hairy than usual. Clypeus with two black dots. Lateral 

 pale patches efface forming nearly right-angled triangles, the upper 

 angle being the right angle. Mesothorax granular, dull. Wings 

 distinctly smoky, nervures dark brown. Marginal rather long, sub- 

 stigraatal portion equal topoststigmatal. Second submarginal nar- 

 rowed about or hardly one-half to marginal. Third discoidal dis- 

 tinct. Fir.st segment of abdomen, except its distal margin, blue, 

 granular, in strong contrast with the piceous remaining segments. 

 P.fallax, which presents a certain superficial resemblance to inter- 

 rupta, differs as follows : 



(1). Its clypeus is shaped like a felt hat, not like a pauama hat as 

 in interrupta. 



(2). The upper angle of lateral face-marks is a very acute angle. 



(3). The poststigmatal portion of marginal cell is distinctly longer 

 than the substigmatal. 



(4). The head and thorax are green, whereas they are blue in 

 interrupta. 



6. Perdita ventralis Fox, Proc. Gala. Acad., 1893, p. 17. cj (as $ ex. err.) ; Proc. 



Gala. Acad., 189.^, p. 116 9. 



The original types, three specimens, were found by Mr. Haines on 

 Margarita Island, L. Cala., in March. Later, the same collector 

 obtained numerous examples including females, on Magdalena 

 Island, also in March. These islands are close together, a little south 

 of the 25th parallel of latitude. 



The $ has the cheeks armed, and the clypeus panama-hat shaped. 

 In the 9 the cheeks are unarmed, and the clypeus differently 

 shaped. In the $ the mandibles are very slender, pointed ; in the 

 9 stout, notched within. In view of these differences, it is at first 

 hard to believe that they are sexes of one species, for all that they 

 agree in the abdomen with its suffused banding, in the mesothorax, 

 etc. 



P. ventralis is smaller than mentzelice and pallidior, and differs by 

 the suffused banding of abdomen. P. mentzelice and pallidior have 

 the mesothorax microscopically tessellate, with distinct sparse 

 punctures ; ventralis has it very shiny, smooth, hairless except the 



