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NINTH ANNUAL REPORT 



clothed with short hairs ; in the abdomen not bulgino^ at the middle, and in lacking the 

 sponge-like gills beneath. The head is wider than the rest of the body, which tapers 

 from the first to the last joints. The prothoracic is as long as, or longer, than the 

 meso-and metathoracic joints together, and the abdominal joints increase in length as 

 they diminish in width. The legs are nearly thrice as long as the width of the thoracic 

 joints; the claws are movable and about J as long as the tarsus ; the tibia and tarsus 

 are sub-equal ; the lemur somewhat longer ; the coxa and trochanter about as long as 

 the femur ; there is a whorl of bristles toward the end of the femur and of the tibia. The 

 mandibles are stout, with two principle teeth, the basal with 3 notches and the terminal 

 one finely serrate : the maxillae are elongate, reaching beyond the jaws, and with a 

 simple inner and a 2-jointed outer palpus, both having basal folds, which often look 

 like a basal joint : the antennse are 3-jointed, and reach beyond the jaws, the middle 

 joint longest, the terminal one nearly as long, and tapering: the labium is elongate- 

 quadrate, tipped with two small.tubercles, and with the palpi 2-jointed — the joints sub- 

 equal. A few hairs occur on the sides of the abdomen between the filaments. 



The fact that the young larva lacks the spongy masses of short 

 fibres which characterize the mature larva, and which have been 

 looked upon as accessory gills, would indicate that their purpose is 

 rather to assist the creature, when it gets large, in adhering to the 

 surface of stones at the bottom of swift-flowing waters. Though the 

 larva can live for some time out of water, even when young; yet, un- 

 til it attains its growth it is strictly aquatic, abounding most in rapid 

 flowing streams, and especially such as have a rocky bottom, upon 

 which it crawls slowly about, feeding upon other aquatic insects, 

 especially Ephemerid larvas, some of which, taken from the stomach, 

 I have been able to recognize as belonging to the genus Palingenia. 



Mr. J. H. Comstock of Cornell University, 

 [Fig. 32.] -^jjQ ^g^g ^Q^ several years studied the 



habits of this larva around Ithaca N. 



Y., generally finds it in the most rapid 



portions of streams, where it dwells 



mostly under stones. He has captured 



numbers by turning over large stones 



and allowing the current to wash the ^^ 



larvje into a dip-net; and he is of the 



opinion, which my own observations 



support, that the species lives three 



years in this larval condition. 



By carefully studying the anat- 

 probable omy of the species, he has also discov- 

 UELo^TOMA.ered an additional pair of rudimenta- 

 ry spiracles on the hind part of a prominent 

 fold between the meso- and metathoracic joints. 



As to the nature of the eggs (Fig. 82) that BELosTo^^A grandis. 

 have hitherto been mistaken for those of Corydalus, I can only sur- 



