606 NEUEOPTERA. 



to rushes or other aquatic plants. They are of a cylindrical 

 form, terminating at the top in a sudden point ; they are at- 

 tached side by side with the greatest regularity." The larvae, 

 as in those of Corydalus, are broad and flattened, with a pair 

 of long, thick, respiratory filaments attached to the side of 

 each ring of the abdomen. The body of the pupa is curved, 

 with the wings laid along the breast, much as in the Phry- 

 ganeid pupae. The larva is active and predaceous, being 

 armed with strong jaws. When full-fed it leaves the pools or 

 streams in which it has been living and makes an earthern cell 

 in the bank, in which the inactive pupa undergoes its remain- 

 ing transformations. 



In Sialis the prothorax is large and square, almost equal in 

 size to the head ; there are no ocelli ; the antennae are filiform, 

 and the wings irregularly net-veined, the veins being stout. 



The fourth joint of the tarsi is 

 dilated and twice lobed. The 

 larva is much like that of Cory- 

 dalus, but differs i?i having the 

 abdomen terminating in a 

 "long and slender setose tail." 



Sialis infumata Newman (Fig. 593, caudal appendages of the 

 male, from Walsh) is black, with the head not narrower be- 

 hind, while S. Americana Rambur is rust-red, and the head is 

 narrower behind. The wings expand about an inch. 



Chauliodes is a much larger insect, with a quadrangular pro- 

 thorax nearly as large as the head. There are three ocelli 

 placed close together, and the antennae are either pectinated or 

 serrated. The wings are veiny, the transverse veins slender. 

 The joints of the tarsi are cylindrical, and the caudal appen- 

 dages of the male are conical and simple. Walsh describes the 

 larva of C. rastricornis Rambur as resembling that of Cory- 

 clalus, but being much smaller, measuring 1.60 of an inch, and 

 the abdomen has one segment less, with no caudal setae, "so 

 that Chauliodes forms a connecting link in this respect between 

 Corydalus and Sialis, the larva of which is said to have 'one 

 long, slender, setose tail,' " and the under side of the abdomen 

 is " entirety destitute of the remarkable paddle-like branchiae 

 found in Corydalus." The pupa resembles that of Coiydalus. 



is. * 



