198 Mr. J. O. Westwood's Description 



stance between a Coccinella and a Chrysomela. And Mr. Yates 

 thus found Spilosoma erminea and luhricipeda together. The three 

 last named observations were communicated to me by the late 

 Mr. Haworth. 



Gistl has also recorded (in the Isis for 1827, p. QiZ5, cited in the 

 Bulletin des Sciences Nat., February, 1828) a similar occurrence 

 between two allied species of Chrysomela, Ch. menthce and Ch. 

 polita, which he is thence induced to consider as the legitimate 

 sexes of one and the same species ; but this cannot be the case, 

 as one of these species, Ch. polita, is sufficiently common in this 

 country, whilst the other has never been detected. 



Mr. Hope stated at the meeting of this Society, on the 4tli 

 January, 1836, that a similar occurrence had been observed 

 between Blaps fatidka and Aids rejlexa. 



M. le Comte Saint Fargeau communicated to the Academic 

 des Sciences a notice concerning the genus Volucella, the species 

 of which appear, according to this author, to have a kind of 

 binary relationship together, not only in the habits of the larvae, 

 and in the general appearance of the insects, but also in the fact 

 of their being not unfrequently found united together. Thus he 

 exhibited instances of this occurrence between F. homhylans and 

 V, plumata, " oCx les deux sexes de ces especes jouoient un role 

 inverse dans cette action," (Enc, Meth. x. p. 784). He did not 

 succeed in tracing the result of this occurrence, but he mentions 

 that a specimen which he possessed of a Volucella, resembling 

 V. plumata in the colour of the anterior part of the body, and 

 V. homhylans in the terminal segments of the abdomen, seemed to 

 have been the result of such an union, and to prove the fecun- 

 dating power of the insects under such circumstances. 



In the first volume of the Annales de la Societe Entomologique 

 de France, various observations are recorded upon the coupling of 

 species hitherto regarded as distinct. Thus, M. Rambur con- 

 siders that Sphinx vespertiUoides is a hybrid between Sph. vespertilio 

 and Sph. hippophaes, and that Sphinx epilobii is a hybrid between 

 Sph. vespertilio and Sph. euphorhice. M. Lefebvre also has re- 

 corded the observation of two species of Tortricidce, supposed to 

 be specifically distinct, in the act of copulation, but which he is 

 induced from thence to regard as the legitimate sexes of the same 

 species. The same author also mentioned an observation, com- 

 municated to him by Treitschke, in which Zygoena Jilipendulce j 

 was found coupled with a yellow variety of Z. ephialtes $ , which 

 had been observed by Treitschke, who was thence induced to 

 regard the red variety of Z. ephialtes as the result of this union, 



