WINTER INSECTS OF EASTERN NEW YORK. 239 



abdomen. The scales which occupy the place of the wings in the females 

 are but faintly perceptible, appearing like two minute greyish-black spots 

 on the thorax. In the living insect, there is a light fulvous vitta, obvious 

 to the naked eye, along each side of the abdomen, at the lateral suture; 

 this is frequently obliterated or but imperfectly discernible in the dried 

 specimen. 



So far as I have at present observed, this appears abroad earlier in the 

 season, and in colder weather than the preceding, though occasionally 

 found associated with it on the last snows that fall in the spring. It is 

 much less common than the other. 



3. Perla nivicola. ['^] The Small " Snozv-fly." 



Black ; wings grey, unclouded, a third shorter than the abdomen in the 

 males, a third longer in the females. 



Length 0.20, wings expand 0.45 ; males smaller. 



Hcadsh.\m.x\g, clothed with very short, fine hairs. Palpi brownish- black, 

 sub-diaphanous. Antennae reaching half the length of the wings, black, 

 setaceous, about thirty-jointed ; joints obconic, basal one largest. Pro- 

 thorax flattened, its margins more smooth and shining, its disk rugulose, 

 with a few shallow impressions ; an impressed transverse line near the 

 base and another near the apex. Abdomen shining, with a broad pale ful- 

 vous dorsal vitta which does not extend on to the two last segments ; ven- 

 ter with a tint of obscure pallid at base. Setae as long as the abdomen, 

 black, setaceous, clothed with short whitish hairs ; joints from thirteen to 

 about eighteen in number, obconic, gradualh^ shorter toward the base. 

 Legs black, joints cjdindric. Tibiae obscure pale brown except at the tips, 

 subdiaphanous, grooved longitudinally. Tarsi, basal joint longest, second 

 joint very short. Wings reaching half the length of the setas, finely cili- 

 ated at their tips and along their inner margins ; gray, diaphanous, im- 

 maculate; nervures black, robust, and very strongly marked, particularly 

 on the upper pair which have five closed cells in the disk. The male is 

 smaller, with the wings reaching but two-thirds the length of the abdo- 

 men, its palpi and entire tergum black, and the tibiae darker than in the 

 female. 



On warm days in the latter half of winter this species may be observed 

 crawling with hurried steps upon the snow. It becomes most numerous 

 about the time the snow finally disappears, and is then often seen on 

 shrubs, fences, and buildings, and not unfrequently finds its way into our 

 houses. It is extremely common, occurring most abundantly in the vi- 

 cinity of streams of water, in which element the previous stages of its 

 existence are passed. When first excluded from its pup.a state, it is of a 

 pale yellowish color, but gradually changes to black, this change com- 

 mencing upon the thorax. Copulation occurs immediately after the female 

 comes from the pupa state. 



[* Is Capnia pygmm (Burm.) Tictet: Hist. Nat. Iu3. Neurop., 1S41, p. 324, pi. 40, figs. 

 1-3.1 



