I48 NEW YORK STATE MUSEUM 



segments, the fifth pyrif orm ; the stem one-fourth the length of the 

 enlargement, the tenth and eleventh segments fused though sepa- 

 rated by a distinct stem. Palpi probably quadriarticulate, stout, the 

 first segment subrectangular, slightly swollen distally, the second a 

 little longer, rather stout, the third probably longer than the second, 

 more slender. Mesonotum dark brown, the submedian lines sparsely 

 haired and irregularly tuberculate. Scutellum yellowish brown, 

 postscutellum and abdomen fuscous brown, genitalia dark fuscous 

 yellowish. Wings hyaline, costa yellowish brown. Halteres yellow- 

 ish transparent, legs a variable yellowish or yellowish brown, the 

 distal tarsal segments somewhat darker; claws probably simple. 

 Genitalia ; basal clasp segment rather stout, with a distinct lobe 

 basally and tapering to a subtruncate apex ; terminal clasp segment 

 rather stout at base and tapering to a subacute, thickly setose apex ; 

 dorsal plate rather long, broad, broadly rounded and thickly setose 

 apically ; ventral plate long, slender, subtruncate distally ; style long, 

 slender, acute apically. Type Cecid. 1294. 



Tritozyga H. Lw. 



1862 Loew, H. Monog. Dipt. N. Amer., 1:177, 178-79 



1876 Bergenstamm, J. E., & Low, Paul. Syn. Cecidomyidarum, p. 18 



1888 Skuse, F. A. A. Linn. Soc. N. S. Wales Proc, 3:44, 143 



1897 Kieffer, J. J. Syn. Cecid. Eur. & Alg., p. 53 



1900 Soc. Ent. Fr. Ann., 69:447-48 



191 1 Felt, E. P. N. Y. Ent. Soc. Jour., 19:32 



This peculiar North American form was made the type of a new 

 genus by H. Loew, who refrained from bestowing "a specific name 

 because of the mutilated condition of the specimen. Through 

 the courtesy of Mr Samuel Henshaw it has been possible to study 

 the type, now in the Museum of Comparative Zoology at Cam- 

 bridge, Mass. This species is more closely related to the author's 

 Microcerata than to any other known genus. It is easily separated 

 from Microcerata by the uneven fork of the fourth vein, the pos- 

 terior branch being a nearly straight continuation, while the anterior 

 branch arises at nearly a right angle and describes a broadly S- 

 shaped curve before uniting with the margin. This character alone 

 suffices to distinguish it from all other Itonididae. The fourth, 

 fifth and sixth veins are distinctly heavier than in Microcerata, the 

 last having a somewhat sinuous course. The antennae are com- 

 posed of but 9 segments, the second being somewhat enlarged and 

 the terminal segment, evidently composed of 3 rather closely fused, 

 distinctly produced and with a length fully six times its diameter. 

 The palpi are plainly stouter than in Microcerata. 



