448 Mr. Newport on the Anatomy and 



nosa, they agree with both in every particular, so that I have no doubt of 

 their identity. The species appears to have a wide geographical range, 

 from Philadelphia southward as far north as Canada; and probably is 

 the comtnon species of the North American continent. The larva and 

 pupa of this species have also been taken by Mr. Barnston, and specimens 

 of them, presented by that gentleman, are now in the cabinets of the Bri- 

 tish Museum. As they have not hitherto been described, I may state 

 generally that in size^ colour and markings the pupa closely resembles that 

 of the European species, Perla bipunctata, Pictet*. The larva is smaller, 

 and of the same colour as the pupa, but is less distinctly marked. It is 

 yellow with black bands. Its head is flattened and subtriangular, with the 

 eyes black, depressed, and placed on the upper lateral surface, and on the 

 front there are three minute black points in the place of the future ocelli. 

 The antennae are setaceous, yellow, and have about ninety articulations. 

 The labrum is short, wide, and of a brown colour, and the front has two 

 transverse, waved brown bands. The prothorax is suboval, flattened, with 

 two indistinct black marks on the upper surface, encircled with a black band. 

 The meso- and metathorax are transverse, subquadrate, with the posterior 

 angles and margin dilated. Each segment has an indistinct subtriangular 

 mark in the middle, encircled with a broad black band. The abdomen is 

 yellow, with the posterior margin of each segment on the dorsal surface dark 

 brown, or black. The caudal styles are tapering, yellow, and with about 

 fifty articulations. The ventral surface of the body is entirely yellow, and 

 there are small branchiae on the first and second abdominal segments, but 

 not on the ventral surface of the thoracic. The legs are compressed, with the 

 thighs dilated and the tibiae densely ciliated. 



The pupa differs from the larva in its greater size, darker colour and mark- 

 ings, and in the elongation of the angles of the meso- and metathoracic seg- 

 ments into long triangular rudiments of wings, which, in addition to the 

 black band at the base of each, have also another at their apex. The thighs 

 are dilated as in the larva, and have two brown bands, and the tibiae are also 

 ciliated for swimming. It is entirely without external branchiae. 



The habits of this species have been carefully observed by Mr. Barnston. 



* Loc. cit. pi. 11. 



