Dumeril and Bibr oil's Erpetologie Generate. 285 
Transactions of the American Philosophical Society. It is occupied 
principally with descriptions of various species of Uniones, most of 
them American, with a few from China, and has added greatly to 
our acquaintance with this large genus. To this are appended ob- 
servations on the species of Naiades described by Lamarck; and the 
descriptions of some new species of shells belonging to other fresh- 
water or land families, each species described being illustrated with 
a characteristic coloured figure. 
Mr Lea has charged some of his countrymen with a fault of which 
he is himself not guiltless that of capriciously changing the names of 
several species ; and while he has, rightly perhaps, brought toge- 
ther as varieties several of the species described by other authors, he 
has, in other instances, separated individuals from species on very 
slight differences. Some of his new species have been previously cha- 
racterized. Unio necklinianus, for example, was described many 
years ago by Mr Swainson : U. Murchisonianus and Symphynota 
magninca are described and figured in Griffith's Translation of Cu- 
vier's " Regne Animal," Cyrena Javensis is C. Childrense of Wood's 
Supplement ; and C. rotundata is only the adult of the same species. 
Symphynota bialata is the young state of Dipsas plicata of Dr Leach ; 
Melanopsis princeps appears to be only the young of Pryena ater ; 
the Lymnea imperialis is certainly, nothing but the very young state 
of a Bulimus, probably B. haemastomus ; and the shell on which Mr 
Lea has formed his new genus Aphrodite, and which he considers 
should be placed after the genus Pyrena, is a well known one, fi- 
gured by Chemnitz and described by Lamarck, under the name of 
Cardium Grcenlandicum. It is not uncommon on the coast of Green- 
land, and only differs from the other cardia in the small size of its 
teeth, which are most developed in the younger specimens. Hence 
Montagu, who considered it a new species, called it Cardium eden- 
tula. J. E. G. 
Erpetologie Generate ou Hisloire Naturelle complete des Reptiles. 
Par M. C. DUMERIL and G. BIBRON. Vols. 2, Paris, 8vo. 
THIS work, which forms one of an excellent series publishing in 
Paris under the title of " Suites a BufFon," is intended to give a 
complete history of reptiles. The first volume is principally occu- 
pied with a description of these animals and their organization in ge- 
neral, to which is appended a list of works on the same subjects in 
chronological order. It contains likewise the methodical distribu- 
tion of the Chelonian reptiles into orders, families and genera ; an 
account of their structure and manners, and a list of the authors who 
have treated of them in particular. The second volume contains the 
