OF NORTH \MEIUCA. 83 



BOMBYCID^, 

 ARCTIIN^. 

 Geuus AEACHNIS. Hiibner. 



Fore wings nearly one-third longer than the hind pair, much longer 

 than the body. The subcostal vein forms a small costal cell, immedi- 

 ately behind the origin of the discal vein, and gives rise to a marginal 

 nervule which sends off, near its middle, a short nervule to the costa; 

 near the tip of the wing it sends ofif the post apical nervule, and behind 

 it becomes bifid. The subcosto-inferior arises on a short stalk common 

 to it and the discal vein. The median vein is four-branched, the fourth 

 median being very remote from the third. Hind wings about equal to 

 the abdomen, broader than the anterior pair, with the neuration as 

 usual in the family. 



Head quite small, somewhat depressed, smooth, with ocelli. Front 

 moderately broad, slightly inclined. Eyes very small. Antennce simple 

 in both sexes. Labial palpi rather short, scarcely e.xtending beyond the 

 clypeus, but slightly curved and ascending, and slightly hairy beneath ; 

 third joint short. Tongue exceeding the tips of the palpi by one-half 

 its length. Cletnens, Proc. Acad. Nat. Sci. Phil., p. 525. (i860.) 



But one species is found in the United States, and that is from the 

 Pacific Slope. 



1.— ARACHNIS PICTA, Packard, (PI. 3, fig. 6.) 



Arachnis picta, Pack., Proc. Ent. Soc. Phil., vol. 3, p. 126. (1864.) 

 " $ . — Head bicolorous; front, below the base of antennae, pale slate, 

 above white. Base and tip of palpi vermillion, scales beneath white. 

 Prothorax white, each half with a large round pale slate central spot 

 margined with black. Notum pale slate; patagia margined with black, 

 and a double median black line. 



"Primaries pale slate, with five very unequal sigmoid dislocated white 

 bands, broadest upon the costa and margined with black. Third and 

 fourth consist, below the costa, of disconnected dots, and the fifth is 



