322 



This species occurs generally throughout the state, and in fact in 

 most parts of North America. The larva (PI. XLVII, Fig. 2) is 

 found in rivers and small streams, and differs from that of cincta in 

 its smaller size and in the markings, as stated in key. For fuller de- 

 scriptions and life histories of the two species see Mr. Hart's paper 

 previously cited. 



I have found the larvae abundant in a small stream at Muncie 

 from April to June. 



Subfamily CLITELLARIINAE 



This subfamily does not, in my opinion, form a natural group. I 

 consider that Hcrmetia does not properly belong with the aquatic 

 forms, being more closely allied to Geosarginae in larval characters, 

 but I leave the arrangement as in Williston's "Manual" pending fur- 

 ther information upon the life history of other genera. 



SUBFAMILY CHARACTERS 



Larva and Paparium. — The larvae of the aquatic forms differ 

 from those of Stratiomyiinae in having the apical segment compara- 

 tively shorter, almost subquadrate, and the dorsum with short thick 

 bristles arranged in a transverse series near posterior margin of each 

 segment except the apical. The genus Hcrmetia is terrestrial, re- 

 sembles the larva of Gcosargus in many respects (though much larger 

 than any species of that genus known to me), and has the body slight- 

 ly broadened apically, the dorsum unicolorous, and the head long and 

 tapered anteriorly. 



Key to Genera 



larvae and puparia 



1. Terrestrial species; body not tapered posteriorly; apical segment 



rounded ; opening of the posterior spiracular chamber in the form 



of an unfringed transverse slit at apex of dorsum of last segment 



Hermetic/,. 



— Aquatic species; body tapered anteriorly and posteriorly; apical 



segment elongated and more or less truncated; opening of 

 posterior spiracular chamber fringed with soft hairs 2 



2. Posterior spiracular chamber situated on dorsum of apical segment, 



the fringe of hairs rather short ; apical segment armed with 4 

 long marginal hairs Nemotelus. 



— Posterior spiracular chamber at apex of apical segment, the fringe 



of hairs long; apical segment without the long marginal hairs. . . 

 Oxycera. 



