Feh.,i9i6 Bulletin of the Brooklyn Entomological Society 15 



to me, though I had no doubt as to its being a helomyzid. Being 

 unable to place it in any genus known to me, I made an attempt 

 to obtain the male, hoping that it would clear up certain points 

 for me, and fortunately succeeded in obtaining a single specimen. 

 Much as I deprecate the erection of genera for the reception of 

 single species, there appears to be no way out of it in this case, 

 as the combination of characters possessed by the species is not 

 met with in any genus in the family, and its habitus does not 

 correspond closely to that of any other except, in some respects, 

 to that of Heteromysa. From Heteromysa it is readily separated 

 by the very much more widely separated eyes of the male, the 

 longer costal spines, and the absence of mesopleural bristles in 

 both sexes. Anarostoma is the most closely related North 

 American genus yet described, but its species have mesopleural 

 bristles and, as is the case in all the other genera, the first vein 

 ends proximad of the vertical line of the inner cross-vein or just 

 in hne with the latter instead of very distinctly distad of it as is 

 the case in the present genus. 



Anarostomoides, n. gen. 



Generic characters. — Male, female: eyes widely separated; 

 orbits with 2 pairs of bristles ; postvertical bristles small, cruciate; 

 face retreating, upper mouth-margin not sharply defined ; vibrissae 

 not well differentiated, represented by 2 weak hairs ; cheeks 

 almost subquadrate, nearly as high as eye ; antennae of moderate 

 size, arista subpubescent. Bristles of disc of mesonotum irregu- 

 lar, the dorso-centrals consisting of 7 pairs, the anterior 2 pairs 

 in front of suture ;* humeral bristle present ; mesopleura without 

 bristles ; sternopleura with 2 bristles on the upper posterior angle 

 and numerous long hair-like bristles on the lower portion ; scutel- 

 lum with 6 bristles. First vein ending distinctly beyond the 

 inner cross-vein. 



Type of genus, Anarostomoides petersoni, n. sp. 



Anarostomoides petersoni n. sp. Male. — Black, opaque, the ground-color 

 everywhere obscured with dense grayish pruinescence. Frons slightly 

 brownish or reddish anteriorly ; face reddish testaceous ; antennae deep 



* This may be an abnormal specimen, and possibly the usual number of 

 dorso-centrals is S pairs. 



