402 
POPUIAE SCIENCE EEVIEW. 
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 was effected ; and when they 
are entirely separated from it, organs which were before invaginated like the 
slug’s eye, became everted. Such is the case with the spines of the cephalo- 
thorax, the last joint of the foot jaws, and true feet, the ciliated fringes of 
the temporary swimming organs, and the spines, hairs, and filaments which 
clothe the antenna3 and final somite of the abdomen. — Vide Comptes Rendus, 
December 26th and January 9th. 
Neio Silkworms. — At a meeting of the French Academy, January 23rd, 
M. Guerin-Meneville presented a note on a new sub-genus of Bombycides 
producing silk. The animal is termed Saturnia Bauhinim, and is an inha- 
bitant of Senegal. For this the author proposed to form a new sub-genus, 
under the title of Faidherhia, in honour of General Faidherbe, the com- 
mander of the French military expedition in the district of the Senegal, 
through whose instrumentality the sHk-pToducing qualities of the insect 
have been made known. Each cocoon contains 633 .milligrammes of silk, 
those of the conunon silkworm containing only 290, and those of the silk- 
worms of Ailanthus and Bicinv.s onlj 255 and 175 milligrammes respectively. 
It is proposed to introduce the cultivation of this new silkworm into Algeria. 
— Vide The Reader, February 18th. 
Cervical VertehrcB of the Tvjo-toed Sloth. — Professor Peters read a paper on 
this subject before the Academy of Sciences of Berlin, at one of its meetings 
in December last. The only exceptions to the rule that mammalia possess 
seven cervical vertebrse have hitherto been the genera Bradypus and Manatus, 
the former genus having from eight to ten, and the latter only six, neck- 
bones. The Professor has added another to the list of exceptions : this is a 
species of two-toed sloth, which he described iu 1858 under the name of 
Cholcepus Soffmanni. He has in his possession several skeletons of this 
edentate, and in none of his specimens do the cervical vertebrae exceed six 
in number. 
A Journal of Conchology, to be published quarterly, is about to make its 
appearance on the other side of the Atlantic. It will be entirely devoted to 
Molluscan Zoology, and the subscription will, we understand, be ten dollars 
per annum. 
The Anatomy of Morhkeys has been ably discussed by Mr. St. George 
Mivart, F.Z.S., in a series of papers read before the Zoological Society, 
and which will appear at length in the “Proceedings” of the Society. 
