148 NEW YORK STATE MUSEUM 



segments, the fifth pyriform; 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. ^lesonotum dark brown, the submedian lines sparsely 

 haired and irregularly tuberculate. Scutellum yellowish brown, 

 postscutellum and abdomen fuscous brown, genitalia dark fuscous 

 yellowish. \Mngs 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 Lo2w, H, ^lonog. Dipt. X. Amer., 1:177, 1/8-79 



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



1888 Skuse, F. A. A. Linn. Soc. X. 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. X'. Y. Ent. Soc. Tour., 19:32 



This peculiar X'orth 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 ^Ir 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 

 ^licrocerata than to any other known genus. It is easily separated 

 from ]\Iicrocerata 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 ]^Iicrocerata, 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. 



