660 



Mr. T. D. A. Cockerell — Descriptions and 



width. 33 or 34 scales in a longitudinal series. Dorsal 

 8 or 9 ; origin equidistant from anterior {^) or posterior ( ? ) 

 margin of eye and posterior edge of caudal fin ; fin more 

 elevated in the male than in the female, but not nearly- 

 reaching the caudal when laid back ; distance from doisal to 



Petahsoma amazomim, S a^d $; enlarged to \\. 



caudal twice or nearly twice the least depth o£ the caudal 

 peduncle. Anal 10, in the female nearly in the middle of the 

 length of the fish, in the male originating a little behind tlie 

 end of the pectoral, which is shorter than the head. Pelvics 

 6-rayed, inserted below the middle of the pectoral. Caudal 

 subtruncate. Coloration olivaceous. 



Two specimens, a male of 35 and a female of 51 mm., 

 from Obidos. 



Peialosoma cultratum differs from this species especially in 

 the deeper and more strongly compressed body and more 

 posterior dorsal fin. In the type, a male of 50 mm., the 

 depth of the body is 3^ in the length, the dorsal, when laid 

 back, nearly reaches the caudal, and the distance between 

 these fins is equal to the least depth of the caudal peduncle. 



LXXIV. — Descriptions and Records of Bees. — XXXIX. 

 By T. D. A. CocKERELL, University of Colorado. 



Halictus j)rovancheri, Dalla Torre. 



Comparing specimens from Woods Hole and Cuttyhunk 

 Island, Massachusetts, with those collected by Hobertson in 



