18G NOTES ON CYDOSIA AND CERATHOSIA. 



Mr. Stretch, in the Zygaenidae and Bombycidse of North America, p, 

 161, writes : " X\ CAliMli.K-ZviJAKNi.N.i: — (J en us Cj/dosia.' 1 He gives a 

 somewhat general description of the venation of primaries, but says 

 nothing of the secondaries, the venation of which is so important in 

 fixing the true position of these forms, fie follows Grote and Kobiuson 

 in their comments on its Lithosiid analogies, and also remarks on its re- 

 semblance to the Tineidce. The species he leaves as they were, but sug- 

 gests thai the species identified as nobilitella by Grote and Robinson is 

 not Cramer's species, but an allied one, for which he proposes the term 

 imitella, should his suggestion prove correct. No differences are given, 

 as Mr. Stretch, not having access to Cramer's works, could not with 

 certainty identify his species. In 1873 Mr. Grote, in Bull. Buff. Soc. 

 X. Sci., vol. 1, catalogues the Zygaenidae of North America, including 

 Cydosia therewith. He, however, makes it the type of a new subfamily, 

 which he calls Cydosiina', containing this genus only. No characters 

 are giveu, and no reasons for this separation. He accepts Mr. Stretch's 

 view that the Texan form is not the same as Cramer's species from 

 South America and the West Indies, but now suggests that the two 

 species, aurivitta and imitella, are merely forms of one variable species. 



Nothing is here added to our knowledge of the structure of the 

 spec it-s. 



In the list of 1882 Mr. Grote retains the same classification, and 

 makes imitella Str. a variety of aurivitta G. & R. Penthetria Hy. 

 Edwards is added to the Gydosiince without comment or question. 



Recently Mr. Edwards removes his genus to the Hetergynidce, quite 

 erroneously iu my opinion, though he was undoubtedly correct in break- 

 ing up the association with Cydosia. 



In preparing my notes on the so-called Zygaenid genera, published 

 iu Trans. Am. Ent. Soc, 1885, vol. 12, pp. 77-84, I had no specimen of 

 Cydosia at hand for study, and I simply referred to it as of uncertain 

 location. 



In the Stettiner Ent. Zeitung, 1885, vol. 46, pp. 203-208, Mr. H. B. 

 Moeschler reviews my paper, and fully agrees with my disposition of the 

 majority of the genera. Of Cydosia, which he appears to know well, he 

 says it is unquestionably Lithosiid. 



Recently, in a little lot of odds and ends shown me, I found a frag- 

 mentary, rubbed specimen of C. aurivitta and took the opportunity of 

 glancing at the venation. I saw at once that the venation was, as 

 Moeschler suggests, Lithosiid. This induced me to examine the Museum 

 collection, which contains a considerable number of both aurivitta and 

 imitella, and I was easily able to make out the entire venatiou, which 

 was completely Lithosiid. An examination of the head, however, 

 showed a prominent clypeal protuberance and very distinct ocelli, 

 making the genus Arctiid and closely allied to Cerathosia Smith. From 

 this latter it differs in lacking the claw of the fore tibia and the acces- 



