Miscellaneous . 237 



M. Pruner-Bey. The latter and M. Gratiolet showed that the pro- 

 gnathism of this isolated jaw did not indicate any real resemblance 

 to the Quadrumanous type. The cranium discovered by M. Van Be- 

 neden fully confirms this view ; for in this the cerebral development is 

 perfectly Human, and the frontal region in particular presents a 

 remarkable extent. On the other hand, the well-marked braehy- 

 cephalism of this cranium forbids all approximation to the negro 

 type. — Comptes Rendus, December 2(5, 1864, p. 1087. 



Note on the Metamorphoses of Marine Crustacea. 

 By M. Z. Gerbe. 



After referring to the researches of M. Coste and himself, which 

 led them to the conclusion that the larvae of the Palinuri are iden- 

 tical with the Crustacea described by naturalists as forming the 

 genus Phyllosoma, the author states that, as several zoologists are still 

 doubtful of the truth of these results, he gives a description of the 

 observed facts, in proof of the opinion above mentioned. 



The larva of the Palinurus of our seas manifests those general 

 characters which have been described in the exotic species of Phyllo- 

 soma — as, for example, the absence of branchiae, and the flattened, 

 membranous, diaphanous body, divided into two bucklers, one of 

 which, of larger size and rounded form, constitutes the head, and 

 supports in front four antennae and two pedunculated eyes, whilst 

 the other, smaller one, terminated posteriorly by a short and slender 

 abdomen, bears the footjaws and true feet, furnished with ciliated 

 appendages. 



This larva does not, indeed, correspond completely with the cha- 

 racters of the genus Phyllosoma : thus it presents no trace of the 

 false feet which are attached to the abdominal segments of Phyllo- 

 soma ; the last of these segments is simple, instead of being termi- 

 nated by a fin composed of five laminae ; and, lastly, it only exhibits 

 two pairs of footjaws and three pairs of true feet. 



Hence it would atfirst appear that the embryo of Palinurus vulgaris 

 is not a Phyllosoma, as it does not present all the characters of that 

 genus. But these are in reality only transitory differences, which 

 will be successively effaced in the course of the first four or five 

 changes of skin. Even at this period, some of the organs which 

 these moults are to bring to light are represented by excessively 

 rudimentary buds, with corresponding nervous ganglia and divisions 

 of the sternal artery ; the first two footjaws and the last two pairs of 

 true feet are in this condition. 



On witnessing the hatching of the marine Crustacea, and following 

 their development, we find that all make their appearance in a larval 

 form, and that, immediately after their birth, all of them undergo a 

 first moult. They detach themselves from the epidermal envelope 

 in which their ovarian development has been effected ; and when they 

 are entirely freed from it, organs which were previously invaginated, 

 like the pedunculated eyes of the Snails, become everted. Of this 

 sort are the spines which arm the cephalothorax of most of them 

 (especially the larvae of the Zoea-ionv), the last joint of the footjaws 



