5If Bulletin No. 159 



with two claws, these sometimes double and often re- 

 inforced by curved spines. Prothoracic shield longer than 

 wide, large. Middle and posterior thoracic somites with 

 small transverse shields. Abdominal somites with a hairy, 

 tapering, lateral filament on each side; beneath and within 

 the filaments of each side are tufts of slender branchial 

 filaments on the abdominal somites one to seven, inclusive. 

 A pair of terminal false feet present, each with two long 

 curved claws and a filament, like those along the sides, but 

 more slender. 



\ 



Fig. 23. — Larva of grampus or hellgrammite (Corydalis corn7ita\. x V2. 



It was constantly met prowling about under rocks, often 

 with its body coated with mud and refuse, as if for conceal- 

 ment. Its eyes are in a cluster on each side of the head, but 

 are not conspicuous in the large larvae because of the dark 

 hue of the whole animal. Younger larvae presumed to be 

 this have the head and first body division reddish brown, 

 marked with black, and the black eye-specks are con- 

 spicuous, forming a cluster on each side of the head, one of 

 them occupying the center, the rest ranged in a curved 

 series about it, the ventral median one smaller than the rest. 



The smallest larva of the family collected is white, and 

 the branched respiratory structures of the abdominal somites, 

 consist of a basal piece and several simple branches, as in 

 some of the case-fly larvae described. Possibly it is a differ- 

 ent species. It was taken in the Left Fork of Straight 

 Creek, September 1, 1911. 



EPHEMERIDA (MAY FLIES). 



Perhaps the commonest insects inhabiting the swift 

 waters collected from about Pineville and indeed everywhere 



