62 Zoological Society. 



4. Description of a new species of Box Tortoise from 

 Mexico. By J. E. Gray, Esq., F.R.S. etc. 



In a collection of reptiles recently received from Mexico are two 

 specimens of a Box Tortoise, which, beside differing from the com- 

 mon box tortoise of North America, in being of a more elongated 

 form, both agree in two characters, which are not found in that 

 species or in any other species of the genus ; first, in having an 

 additional vertebral plate ; and secondly, in the hind feet being only 

 armed with three large claws : there is no appearance of the fourth 

 claw, and even scarcely any rudiment of the fourth toe found in the 

 other specimens of this genus, and in all other Emydce. 



This species will form a section or subdivision of the genus, which 

 may be called Onychotria. 



Cistudo (Onychotria) Mexicana. Three-toed Box Tortoise. 



Shell oblong, dark-brown, pale, spotted and rayed, spot and rays 

 sometimes confused. 



Vertebral plates with a nearly continued keel, and with a small 

 intermediate one between the usual fourth and fifth plates. 



The hinder margin acute revolute. 



The head pale brown ; the legs yellow or orange spotted, with five 

 unequal claws. 



The hind legs brown, uniform, with only three large claws, the 

 middle and the front one largest. 



The sternum flat ; the gular plates wide in front, and suddenly 

 narrowed behind. 



Hab. Mexico. 



There was a specimen of the Kinosternon scorpiodes, and of the 

 Gopher, Testudo gopher, in the same collection : the latter only dif- 

 fered from the usual North American specimen in being rather larger 

 and blacker. 



February 27. — William Yarrell, Esq., Vice-President, in the Chair. 

 The following paper were read : — 



1. Description of seven new species of Marginella. 



By John S. Gaskoin. 

 Marginella quadrilineata. Marg. testa oblong o-ov at d, pal- 

 lide virescente, nitidd ; lineis rufis quatuor, equidistantibus, 

 transversis ; basi rotundatd, Icevi ; aperturd lata antice prce- 

 cipub ; canali latissimo ; labio lato, marginato, ultra apicem 

 extenso ; columelld antice quadriplicatd, plicis duabus anticis 

 concur rentibus canalem intermediam formantibus ; apice oblito. 

 Shell oblongo-ovate, of an uniform, opaque, pale-greenish colour, 

 highly polished, with four distinct, nearly equidistant, very narrow, 

 uninterrupted, even, red lines or bands, surrounding the shell from 

 the upper or outer edge of the incrassated margin of the lip, which con- 

 tinuing within the columella, extend over the earliest formation of 

 whorls : these lines are equally conspicuous on the inside of the last 

 whorl, and no doubt throughout the whole inside of the shell. The 

 same pale-greenish colour pervades the inside as the outer part ; base 



