1886.] PROCEEDINa§ OF UNITED STATES NATIONAL MUSEUM. 415 



genus has strong Cossid tendencies and in any natural arrangement 

 must stand very close to them. Hemileuca is very closely related to 

 Clisiocampa^i\>u(\. so also seems Pseudoliazis : Euleucopliceus I have seen, 

 and it has simply pectinated antennae — what its venation is I do not 

 know. 



The material from which this revision was made is principally my own 

 collection, in which most of the species are represented. The museum 

 collection furnished a large amount of material for comparison, while 

 Messrs. Hy. Edwards and B. Neumoegen, of New York, kindly loaned 

 me typical examples of some species from their collections, and Prof. Hy. 

 Snow, of Lawrence, Kans., brought with him on a recent visit to Wash- 

 ington some rarities for examination, including Quadrina, Glover ia and 

 Coloradia, the precise position of which could not have been other- 

 wise determined. As some of the insects included in this revision are 

 of the most interesting and largest of oar species of uight-ilying Lepi- 

 doptera, they have been figured and described in almost every work on 

 insects and in almost every treatise on economic entomology. The lit- 

 erature of the species has thus become an enormous one and I have not 

 pretended in this paper to do more than cite the most important or most 

 accessible works. The male genitalia have been examined in almost 

 every species, and figures of the parts are given;' but, though the draw- 

 ings and descriptions are accurate so far as they go, there are yet some 

 structures of importance that have been left untouched simply because 

 our knowledge of these structures in the Lepidoptera is so imperfect 

 that I have not been able to give proper value to them and preferred 

 to omit their consideration here altogether. 



ATTACIN^. 



The AttacincB express perhaps the highest point in Bombycid devel- 

 opment. The imago is absolutely incapable of feeding, and the procrea- 

 tion of the species seems the only point looked to ; in consequence the 

 body of the 9 is very stout and heavy, and filled to its utmost capacity 

 with ova. The insects are strictly nocturnal, and despite the fact that 

 they are usually common, are not often found as imagoes. The larvae 

 are all spinners, and all make strong double cocoons. 



In addition to the family and sub-family characters heretofore men- 

 tioned, none of the species have more tban 11 veins to primaries, and 

 most have only 10 ; the accessory cell is always wanting. Briefly the 

 venation is as follows: Primaries, one internal vein, median three 

 branched (v. 2, 3, and 4), 5 and 6 from the end of the sub-costal, 7 and 

 8 on a long stalk from middle or outer 3d of subcostal; i^ when present 

 out of 8 at variable points, 10 sometimes from the sub-costal and some- 

 times out of 8 ; 12 as usual, from the base. Minor agreements and dif- 

 ferences will be noted in treating of the species. 



