282 THE CANADIAN ENTOMOLOGIST. 



assigned the imago by Mr. Marlatt, since the larva was so different from 

 other Pachynematus larva? he had bred. He says : " I was much 

 surprised that the flies should belong to Pachynematus. The larvss of 

 this genus are solitary grass feeders, whereas a larva very similar to this 

 species is described as that of a species of Fristiphora.'^ 



On making a careful study of the type, I find it really belongs to the 

 genus Micro?iematus, Konow, and has nothing to do with Pachynematus. 

 This result was a great surprise to me, because Mr. Marlatt, in speaking 

 of the genus Micronematus, says : ''This genus seems to be of doubtful 

 value, and at least has no American representative." 



The genus, as my table shows, is a good one, falling near 

 Fristiphora, where Dyar would have it placed from larval characters, 

 and it is quite evident that Marlatt misinterpreted some of Konow's 

 characters, since the genus as tabulated by him cannot be recognized. 



The family Neinatida, as here defined, may be divided into two 

 subfamilies as follows : 



Table of Subfamilies. 



Lanceolate cell widely contracted at the middle and 



closed Subfamily I. , Cladinte. 



Lanceolate cell petiolate Subfamily IL, Nematina?. 



Subfamily L — Cladin.*:. 

 The species belonging to this subfamily are readily distinguishable 

 by the widely-contracted lanceolate cell, the contracted part uniting with 

 the submedian vein and leaving a closed cell at base. 



To this group belong five genera distinguishable by the aid of the 



following table : 



Table of Genera. 



Second submarginal cell receiving both recurrent nervures 4. 



Second and third submarginal cells each receiving a recurrent nervure, or 

 if the first transverse cubitus is wanting it is the first and second 

 submarginal cells which receive the recurrent nervures. 



Male characters 2. 



Female characters. 



Antenntu somewhat compressed, with a sharp projection at tip of 

 basal joint, the third joint with a sinus beneath at the middle, 

 so that the joint is narrower at middle than at the base or 



tip , Cladius, Illiger. 



Antennae normal, cylindrical, not compressed, claws cleft, 



