124 



BRITISH LEPIDOPTEEA. 



into a post-spiracular wart, a characteristic feature of the stirps to 

 which the Noctuids and Notodonts belong. The other characters of 

 this stirps,' viz., the approximation of tubercles iv and v, and of i and 

 ii, are, in those larvae that have these tubercles best developed, well 

 exhibited. The Lasiocampid larva agrees with the Eupterotid in the 

 above characters, tubercle iv, too, being, in both, larger than v, 

 although the absorption of the warts has gone on farther in the latter 

 than in the former. The gregarious habits of our European species, 

 Cnethocampa processioned, C. pityocavipa, etc., are very similar to those 

 presented by Eriogaster and Clisiocampa. The egg and pupa also 

 suggest this as their correct position. 



It is now generally conceded that the Endromid larva shows traces 

 of Lasiocampid, Saturniid and Sphingid relationship, and this is borne 

 out by the characters of the egg, pupa and imago. Kirby unites 

 the Endromids with the Bombycides, and simply gives Endromis 

 generic value in the latter superfamily. The Endromid and Sphingid 

 larva? tend to specialisation of the tubercles by atrophy, as in the Lasio- 

 campids. The newly-hatched larva? of some species of the latter, 

 show that the usual tubercles (many-haired warts) are present, even when 

 they are not traceable in the later skins. This atrophy of the tubercles 

 is accompanied by a specialisation (1) in the development of secondary 

 hairs in the Lasiocampids, (2) in the development of protective colora- 

 tion in the Endromids and Sphingids. The general texture and aspect 

 of the larva and pupa of Endromis are Citheroniid ; a pupa of Endromis 

 versicolor is not at all unlike that of Citheronia imperialis, or of some 

 of the African species that pupate underground. It is difficult, how- 

 ever, once full obtect rank has been attained, to find good struc- 

 tural characters for differentiation, the latter are so very uniform. 

 The larva of Endromis is, in some respects, more generalised than that 

 of most of the Saturniids, and whilst Poulton claims that the Sphingids 

 have been derived from the Saturniids, through the Ceratocampidae, 

 Packard believes that they came from a form more nearly resembling 

 the Endromid larva. Packard is inclined to think that all the Bomby- 

 cids, except the Arctians and Lithosians (which most certainly are not 

 Bombycids, and do not belong to the same stirps as the latter) may 

 have been evolved before the Sphingids appeared. This would make 

 the latter the most recently evolved superfamily of this stirps, and as 

 Packard says that the characters of the head, antennae, thorax, and 

 neuration separate widely the Sphingids and Ceratocampidae (Cithero- 

 niidae), it is practically certain that the origin of the former from 

 Ceratocampid ancestors must have been remote, and that numbers of 

 forms that originally connected them must now be extinct. Poulton 

 claims^ that by means of various tropical larva?, intermediate in 

 some characters between the Ceratocampid and Smerinthid larva?, 

 the Sphingids are to be derived from the Ceratocampids. He 

 attempts to show that certain Sphingid larvae, Ceratomia quadricornis 

 from N. America, and LophostetJius dumolinii from Africa, combine the 



* In the Sphingid larvsa, the tubercles are single-haired and small, and 

 gradually become atrophied (or may be traceable) until the last stage. In Endromis 

 the tubercles are many-haired warts, as in the Lasiocampids, and they are lost 

 (except the lateral thoracic tubercles) at the first moult, and are replaced by shagreen 

 tubercles. 



f Trans. Ent. Soc. Lond., 1888, pp. 568 et seq. 



