444 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.43. 



of Columbia. The species attacks Camfonotus pennsylvanicus. I 

 have also seen one specimen from Cranmoor, Wisconsin. June 12, 

 1910 (C. W. Hooker). 



APOCEPEIALUS SIMILIS, new species. 

 Plate 38, figs. 7, 12, 13. 



This is similar in practically all respects to the above species, but 

 differs in having the ovipositor of the female much narrower at base 

 than in pergandei. In every other respect it agrees with this species 

 and I should have considered it as only a variety of pergandei had it 

 not been for the constancy of the form of the ovipositor in the series 

 of that species before me, and the fact that it came from a widel}^ 

 different locality — Madero Canyon, San Rita Mountains, in Arizona, 

 and attacks a species of Camponotus which, while unable to decide 

 exactly what it is, Mr. Rohwer assures me is not pennsylvanicus. 



I have hesitated to tabulate the males of this genus, as it is difficult 

 to assign them to the proper species without their being taken at the 

 same time and place, none of this sex having been previously described. 

 However, I have obtained three specimens that represent different 

 species and consider that it may be better to indicate their characters 

 so far as my limited material will permit. 



TABLE OF MALES. 



1. Halteres black, small species, under 1 mm aridibs, p. 444. 



Halteres yellow, larger species, 1^2 mm 2. 



2. Third costal division one-third as long as second, 10-11 costal bristles from end of 



first vein to end of costa.' pergandei, p. 443. 



Third costal division one-half as long as second , 6-7 costal bristles from end of first 

 vein to end of costa ? similis, p. 444. 



APQCEPHALUS ARIDUS, new species. 

 Plate 41, fig. 7. 



Male. — This species is easily known from the others in the genus by its 

 comparatively small size. Yellow-brown, subshining; frons distinctly 

 shining, about as long as broad, second pair of bristles as in pergandei 

 Coquillett, antennae yellowish-brown, third joint not elongated as in 

 other species but almost round, of rather small size, arista thick and 

 short, not longer than breadth of frons, nearly bare, mesopleurse bare, 

 anterior scutellar bristles very minute, lower part of pleurae yellow; 

 abdomen dark brown, second segment elongate, third to fifth gradually 

 decreasing in size, sixth elongated, hypopygium yellow, glossy, large, 

 globular, ventral processes large, protruding, anal protuberance very 

 long, with two terminal hairs; legs entirely yellow, hind tibial ridge 

 pronounced, the setulse weak and widely placed ; wings rather broad, 

 costa to short of middle, first division distinctly but not greatly 

 longer than other two together, third division about one-third as long 



