76 ^.v /.v/Vvwrr/yav TO >CK 



It : in tlic nymphs of these ii >y lifting 



<>m the water of swiftly flowing streams the young stone-flies 



may be found closely adhering to their ' 



I 1 surface. They present a wonderfully flat- 



\ I tened appearaii : the body i 



JflK . and closely applied to tli 



while the legs, antenna-, and caudal 

 . diate from it on the surface of the stone. In 



XjjJ jti/' our Common forms their is a tuft of hair- 



mf hke tracheal gills just behind the base of 



W**^~" each lei;. And the more mature individuals 

 present conspicuous wing-pads. 



The nymphs of stone-Hies constitut 

 / \ important element in the food of fislu 



/ \ have found them more often than any other 



/ \ insects in the stomachs of brook trout. 



When about to transform to the adult 

 state the insect crawls from the water upon a 



FIG. 73. Nymph of Stone-fly, , , .-r, 



eum. stone or some other object. Their exuvui: 



common in these situations. The females of certain exotic spe- 

 have been observed to carry their eg^s about with them, 

 attached in a globular mass to the end of the abdomen, for some 

 time before they are laid in the water. Probably our species pre- 

 sent a similar habit. 



The greater number of our species belong to the genus l\rla. 

 In this genus the wings have but few transverse veins; the anal 



the posterior wings is large and folded; the palpi are 1 

 tie-like; and th two caudal setaj. The genus /'/<' 



it scientific interest, owing to the present 

 iieal gills throughout the entire life of the insects. The gill 

 I'teronarcys consist of little tufts of short slender filaments, of which 

 there is a pair on the ventral aspect of each thoracic, and the fi 

 and M-cond abdominal segments. The wings in this genus 



net-veined. 



Thi g of stone-flies that appear in the adult 



Upon the :i warm days in the latter half of winter. 



come more numerous in early spring, and often find their 



into our houses. The most common one in Central New York 



v-fly. Capnia pyguuea. It is black, with gray hairs. 



The female mm. in length, and has an expanse of wings 



of 16 mm. The male measures .only 4^ mm. (0.18 incln, and has 



i 



