55 



Gualon. — This larpje species of Grebe produces an egg of 2 in. ^ in 

 length by lį in. in breadth, of a duU white, stained with earlhy 

 brovvn. 



Podiceps Kalipareus, Quoy and Gaim. Tbe Chilian name Gualita 

 de la Mar. — The egg of this Grebe measures 1 in. y^^ by lį in., of a 

 dull \vhite, some of them more or less stained with dirty brovvn. de- 

 pending ou the number of days they may have been deposited in the 

 nešt. 



The egg of a third species of Podiceps, bearing the Chilian name 

 Gargari, is yet a little smaller than the egg of the Gualita lašt de- 

 scribed, measuring only 1 in. -^^ in length and 1 in. -^^ in breadth ; 

 the colour as usual in the eggs of all the Grebes. 



2. Description of a new Geni's of Emyce. By J. E. Gray, Esq., 

 F.R.S., F.Z.S. ETC. 



In the museum of the Zoological Society is a fine specimen of a 

 large fresh\vater Tortoise, presented by Lieut. Ma\ve, R.N., yvho 

 found it in South America in the year 1833. 



It is marked by Mr. Fraser " Emys Ma\vii, Bibron, original of M. 

 B. 's description, No. 6899," but I can find no such species described 

 in M. Bibron's work, nor is it an Emys as defined by that author. 



It diiFers from all the known Emydse in being covered with very 

 thin membranaceous scales, and in having a broad sternum with a 

 series of four large distinctly defined platės placed over the sterno- 

 costal suture. The gular platės are very small, and there are no 

 axillary or inguinal platės. 



My genus Plaiystemon has the šame kind of sterno-costal platės, 

 but quite a difFerently formed shell. The head is very large and the 

 tail elongate. 



Dermatemys, n. g. 



Ch. gen. — Testą ovalis, gibba, acarinata, in lateribus rotundata, mar- 

 gine posteriore expanso, paulo reflexo, scutellis membranaceis 

 tenuissimis defenso. ScutellcE marginales posteriores latse. Ster- 

 num planum anterius rotundatum posterius emarginatum. Sguama 

 gulares parvse, triangulares, testae superiori per longum symphysin 

 afHx8e. Sutura sferno-costalis squamis magnis ąuatuor defensa, 

 postremis duabus maximis squamis, minima anteriore. Scutella 

 axillares et inguinales nuilsę. Testą vix ad aperturam contracta. 



Head ? Toes webbed ? Claws ? 



Shell oblong, convex, not keeled ; sides rounded, hinder edge ex- 

 panded, slightly reflexed, covered with very thin membranaceous 

 shields. The hinder marginai shields broad. Sternum flat, rounded 

 in front, notched behind : the gular platės small, triangular, united 

 to the upper shell bj-^ a long symphysis ; the sterno-costal suture 

 covered with four large distinctly defined platės ; the anterior smaller, 

 the t\vo hinder largest. The axillary and inguinal jjlates none. The 

 cavity of the shell is scarcely contracted at the opening. 

 Hab. South America. 



