FAMILY ZYGJENIDJB. 13 



Bombjcidae, i. e. the Arctioidea H-S (Arctiidas Leach, 1815,) 

 and concludes the large moths with the Syntomoidea H-S. 



(Glaucopites Newman, 1832.) Then follow the Microlepid- 

 optera. The series of large moths ends with Ctenucha virgo 

 H-S. which he places next to the Crambina H-S. 



In the Catalogue of Lepidoptera Heterocera in the British 

 Museum, part I and II, 1854, Walker adopts the Castnians, and 

 the Zygaenides, as groups equivalent to the Sphingidag and the 

 Bombycidse, but places several undoubted Zygasnid genera, 

 i. e., Cten.ncha, Aglaope Americana Boisd. and Lycomorpha 

 among the Lithosiidas. 



So far as I am aware Horsfield and Moore* are the first 

 authors who virtually placed both the Castniares and Zygsenidas 

 among the Bombycidse, considering them ''from the examination 

 of the metamorphosis" of the genera of these two groups which 

 fell under their observations, as belonging to the Lithosiidae. 

 This work is indispensable to the American student of the 

 Zygaenida3 and Bombycidaa, since it represents the transforma- 

 tion of many Asiatic genera closely allied to those of America, 

 which are not found in Europe. 



I would here draw the attention of entomologists to im- 

 portant characters for classifying the Lepidoptera which have 

 been hitherto overlooked. I refer to the characters drawn 

 from the pieces of which the head and thorax is composed. 

 Each family has a distinct form and size, and a different 

 way of combining the three principal pieces which compose 

 the head: i.e. the occiput which lies behind the ocelli; the 

 epicranium which lies behind the antennae, a.nd the clypeus 

 which in the Lepidoptera generally occupies the "front"' of 

 the head. In the family under consideration and the Bom- 

 bycidae, those parts vary markedly in the different genera, 

 and in each sub-family of these two families there is a 

 distinct form for the clypeus, more especially. There are also 

 two forms in the NorJuidoi which affords to us strong indica- 

 tions for their division into but two sub-families. There is 

 also a distinct form for the Geometridae, the Pyralidae, Tortri- 

 idae, and Tineidse. which gives a peculiar fades to each of 

 these groups. 



The mouth parts : i. e., the mandibles, maxillae and labium 



*A Catalogue of the Lepidopterous Insects in the Museum of Natural History 

 at the East-India House, Vol. n, 1858-59. 



