224 Prof. J. O. Westwood 07i some 



of perfect Lepidopterous insects ivith the larval head are 

 described : — 



Phal^na heteroclita subcristata of O. F. Mueller, 

 Faun. Fredriclisalen, p. 47, and in the Mem. de Matliem. 

 et de Pliys. Acad. A. Sciences Par 1774, vol. vi. pp. 

 508 — 511, pi. 1. This insect (regarded by Mueller 

 as a distinct species, by Hagen, Bibl. Ent. i. 556, as 

 Bombyx dispar, by myself as one of the Noctiiidce, 

 Introd. ii. p. 356, and by Lacordaire as a Noctuelle, 

 Introd. ii. p. 442) appears rather to ho, a specimen of 

 Bombyx Psilura vionacha, as quoted by Werneburg, 

 Beitr. z. Schm. i. 376, and cited by Hagen, p. 6. 



Mueller gives a precise description of the head of his 

 specimen, which was entirely enveloped in that of the 

 larva, which he says consisted of " une membrane mince, 

 qui a I'aide d'une loupe, laissait entrevoir une liqueur 

 transparente agitee d'un mouvement continuel." The 

 moth hved ten days, thus enabling its captor to observe 

 this movement, which he repeats a second time : " On 

 voit clairement le mouvement peristaltique de la liqueur 

 sous la membrane triangulaire aussi bien que le mouve- 

 ment des organes de la bouche," thus proving, as Dr. 

 Hagen suggests, that "the insect must have been an 

 imago with the head of the caterpillar preserved ; not 

 only with the skin covering the head of the imago pre- 

 served, but with a real head of the caterpillar, in which 

 the circulation of the blood was still taking place and the 

 maxillary organs were still moveable, a condition of the 

 parts contrary to all our present knowledge of the 

 anatomy and development of insects. 



Nymphalis populi. — The late Professor Wesmael, of 

 Brussels, captured a specimen of this species near that 

 city, of which he published an account and figure in the 

 Bull. Acad. Bruxelles, 1838, tom. iv. p. 359, with a 

 coloured figure of the insect reproduced in Ann. Sci. 

 Nat. ser. 2, vol. viii. p. 191, and Plagen, ut supra, p. 8, 

 and plate, figs. 10, 11. The specimen Avas fully developed, 

 except that the head was still entirely enveloped in the 

 bicorniited cephalotheca of the larva, Avhich the butterfly 

 ineffectually endeavoured to get rid of by a quick motion 

 of the fore-legs, trying to piish it off. In dissecting the 

 left side of the head, Prof. Wesmael discovered underneath 

 the external skin a second one, much thinner than the 

 outer, and beneath the second one the well-developed eye 



