REPORT OF THE STATE ENTOMOLOGIST. 143 



ent parts of the State. It is the largest of our Nerve-winged insects, 

 and is tolerably common throughout the Eastern and Middle States, 

 and into Ontario. It is so conspicuous and so characteristically 

 marked that, with the accompanying figures, which are of natural 

 size, no detailed descriptions are necessary. 



[Fig. 70] Its eggs (Fig. 70) are oval, about the size of a radish seed, 

 jM and of a pale color, with some dark marks. They are depos- 

 es' *>-^ ited in the summer months in closely-set patches of fifty and 

 « ', ',. ' "pward, upon reeds and other aquatic plants growing along 

 running streams, and the newly-hatched larVcB drop or crawl 

 immediately into the water, which they inhabit till the end 

 of the following spring. The young larva has not been de- 

 scribed, but, judging from analogy, it will resemble the full- 

 grown form, (Fig. 69, a), which is of a dark-brown color, 

 variegated with lighter brown — the abdominal joints being 

 tough and leathery, and the head and thoracic joints horny 

 and polished. 



Most aquatic larvae transform to the pupa state within the 

 water, but this larva quits the water when full-fed, as do the 

 others of the same family, and crawls about for days seeking a place 

 wherein to transform. We find, therefore, that nature has abundantly 

 fitted it for living in both elements, by giving it, first, two rows of nine 

 breathing holes or spiracles, placed in the usual way along the sides 

 of the bod.y, (the first between joints 1 and 2, and the others on the 

 anterior portion of joints 4-10), which enable it to breathe out of the 

 water ; and, secondly, two sets of nine gills or branchias, which enable 

 it to breathe in the water. These gills or respiratory filaments are 

 placed just below the spiracles, and one on each side of each abdom- 

 inal joint, except the 9th, and on the terminal subjoint. They are 

 more or less covered with fine hairs, (inadvertently omitted in the 

 figure), and between them may be noticed small tufts of such hairs. 

 Besides these lateral filaments, there is, ventrally, a pair of rust- 

 brown, spongy masses of short fibres, one on each side of joints 4-10, 

 and a somewhat similar central j)atch on the terminal joint and sub- 

 joint. Dr. Hagen supposes these to be the true gills, but they may 

 be looked upon as accessory gills. The lateral filaments assist in 

 swimming, and we shall also notice, at the tip of the body, a pair of 

 curved, double hooks, which assist in climbing or in moving back- 

 ward. 



This larva feeds on other aquatic insects, such as the larvm of 

 May-flies (J^pliemera family) Shad-flies (Perla family), etc. It abounds 

 most in rapid-flowing streams, and generally in such as have a rocky 

 bottom, upon which it moves slowly about. After leaving the water^ 

 about the' beginning of June, it travels, in the night-time, some- 

 times to comparatively great distances — having been found nearly a 

 hundred feet from its former habitat. At this season, it is sought as 



