OF NORTH AMERICA. 103 



colored. These variations may have been the cause of Walker des- 

 cribing H. angulifera as distinct from his H. Californica. Boisduval's 

 name of H. salicis, was Dr. Behr's MS. name, and was attached to this 

 species many years ago. It is abundant round San Francisco, Cal., 

 and extends as far eastward as the western portion of the State of Nev- 

 ada, and as far north as Vancouver's Island. 



Larva. — Head, body and prolegs entirely black. Abdominal legs 

 pale dirty yellow. Body slightly depressed, densely clothed with evenly 

 cut velvety black hairs, except on the seventh and eighth segments 

 which are bright lemon yellow, with a small black dorsal lozenge- 

 shaped patch of black on each. The caputal and anal segments have 

 numerous slender pencils of pale yellow hairs, much longer than the 

 general clothing of the body, in this respect resembling the larva of 

 H. kssellarts but differing from that of H. Edwardsii, where these pen- 

 cils do not occur. Variety. — In some instances the black hairs are 

 confined to the two anal and two caputal segments, all the remainder 

 of the body being yellow, with black dorsal patches as in the type. 



The cocoon is obtusely oval, tolerably compact and composed chiefly 

 of the hairs from the body of the caterpillar, with but a small amount 

 of silk in its composition. The larva is double brooded, and feeds on 

 the willow ; the first brood appears on the wing, in June ; the second 

 being full fed about the middle of October, and disclosed from the pupa 

 early in the Spring. 



H. Agassizii dci^Qx's, from the other species of the genus found in the 

 United States, in the absence of all tendency to semi-transparency in 

 the anterior wings, such as appears in the thinly scaled tessellaris and 

 Edwardsii ; or to silvery markings as in the case of caryce and argetiiaia ; 

 the costa is also less rounded at the apex than in any of the species 

 mentioned, but the larval characters clearly retain it in the genus. 



