292 T. D. A. COCKERELL. 



liiuli. with its suture with the second constricted ; viewed from the side the shape 

 of tlie first segment may be compared to that of the liead of a young chicken; 

 tlie stigma is, if anything, a little nearer to the base than to the apex of the 

 wing; the marginal cell is excessively narrow and short, and does not. reach the 

 costal margin ; there are only two submarginals, the first long, the second small 

 and triangular, but still larger than the marginal ; it receives the recurrent ner- 

 vure much before its middle; the intermediate tibise are sjiinose at tip, but there 

 is only one spur, ]iroperly speaking: the abdomen is terminated by a single fer- 

 ruginous spine, curving upwards; the eyes are not precisely round, but suboval 



Ilab. — " Found drowned" in tlie college horse-trough, Las Cruces, 

 New Mexico, 1895, one specimen. This is clearly a BmchjcidlH, 

 though there is no trace of a third submarginal cell. It is by this 

 character and the black teguke, that it will be known from B. (ifn(tiis 

 (Blake), which it evidently much resembles. 



This year, at Las Cruces, B. eletjantnlin^ has been taken in ■May, 

 and B. filabrfllux in April and June. 



Oxybeliis >*i>ari<leiis n. sp. — Male about 5.5 mm. long, strongly and 

 densely punctured ; black with yellow markings ; silvery pubescence on cheeks 

 and face; prothorax carinate ; scutellum with an obscure longitudinal keel; 

 squama large, rounded, subovate, not pointed as in emnrflinatns, but having a 

 small and easily-overlooked lateral spine; spine bi'oad, deeply emarginate, the 

 emargination forming a little less than a right angle; jdeurae with minute, ap- 

 pressed. silvery haire; first segment of abdomen deeply longitudinally sulcate ; 

 apex of abdomen roundly emarginate. Antennae dark brown, paler beneath ; 

 mandibles yellow with black tips ; superior border of ])rothorax very pale yellow ; 

 tegulffi and sjiine rufous ; squauiae and an oblique spot anterior to each, yellow ; 

 abdominal bands yellow, more or less interrupted in the middle; last segment 

 rufous; femora black, anterior and middle femora with silvery pubescence and 

 their distal ends yellow; tibije yellow, posterior tibite anteriorly black; tarsi 

 yellow. Wings hyaline, veins piceous. 



i/a6.- Las Cruces, New Mexico (Ckll. 1966, Aug. 24, 1894). 



The specific name is derived from the resemblance which the spine 

 and squaniiB present to the tail with hindmost fins of a fish of the 

 genus Diplodns^ family 8{)aridie. 



One has to consider the possibility of this being a variety of the 

 9 of 0. rm.an/inati(.i. I have a % of eiiianjiiintas, kindly identified 

 by Mr. Fox, which I took in Las Cruces (Ckll. 2486), and it differs 

 in its entirely black prothorax, in the absence of the spots before the 

 squanue, in the shape of the squamte and the spine, etc. It would 

 appear from Robertson's description (Tr. Am. Ent. Soc. xvi, 84) that 

 the spots before the squamse are usual in 9 einargmatus. Robertson 

 saVs, also, sides of })rothorax yellow. 



[Note. — O. apnridens is evidently distinct from 0. cmarginni nfi — the spine is 

 differently shaped and the body more coarsely punctured. — W. J. F.] 



