Dr. J. E. Gray on new Genera of Lizards. 103 



Placosoma cordylinum is described from a specimen iu the Mu- 

 seum at Bonn, on the Rhine, collected by Dr. John Natterer in 

 North Brazil ; and it is probable that the Holaspis Guentheri may 

 also be a Tropical-American form. 



Holaspis Guentheri, A. Smith, MS. 



Bluish brown (in spirits), with three bluish-white equidistant re- 

 gular Hues down each side of the head, neck, and body, and a stripe 

 down the front of the fore leg. 



Hab. ? 



The specimen was purchased in Paris without any habitat affixed 

 to it. 



The tail has been reproduced, and the reproduced part is of the 

 normal form, fringed and toothed on the sides, but of a different (that 

 is to say, uniform dull leaden) colour. 



The second genus has many characters in common with Xantusia 

 of Baird, and will most probably belong to the family Xantusiidce, 

 as proposed in the ' Proceedings of the Academy of Sciences,' Phila- 

 delphia, for 1858, p. 255. 



2. PoRiODOGASTER, A. Smith, MS. 



Head pyramidal ; sides erect ; crown flat, hard, bony, covered 

 with very thin polygonal normal shields ; superciliary ridge bony, 

 solid ; temple covered with a shield ; lower jaw thick, bony, solid, 

 covered with a single series of large broad, thin, membranous shields, 

 which are united in a straight line on the middle of the chin ; eyes 

 circular, large, lateral, without any eyelids ; pupil large, circular ; 

 tongue not retractile, broad, flat, attached nearly to the tip, the tip 

 only obscurely nicked ; teeth simple ; ears oblong, large, with a 

 groove to the angle of the mouth ; tympanum sunken ; nostrils late- 

 ral, anterior in the suture between two nasal shields, the front situ- 

 ated between the upper edge of the rostral and the front odd plate. 

 The sides of the neck and throat covered with round, convex 

 scales of moderate and nearly uniform size. The throat with two 

 folds on each side, and with a cross fold in front of the chest ; these 

 folds are covered with scales of the same size and kind as the rest of 

 the throat. The back of the neck, back, and sides of the body 

 covered with uniform, convex, roundish scales, with numerous scat- 

 tered, larger, prominent, conical, tubercular scales placed in longi- 

 tudinal rows along the centre of the back, and larger and more abun- 

 dant ones on the sides. The belly covered with cross series of square 

 flat smooth shields, most of which have a dark large pore-like crypt in 

 the middle of their hinder edge ; the shields of the chest are smaller, 

 more numerous, and placed in converging lines. The legs strong, 

 covered with round convex scales ; the hinder ones armed with 

 larger prominent tubercles on the upper surface. Toes 5 : 5, unequal, 

 slender ; claws sharp, curved, the under surface covered with flat 

 shields ; femoral pores large, distinct. The front of the vent covered 

 with three pairs of equal flat shields, each having a very large crypt 

 in the middle of its hinder edge, the hinder pair next the vent being 

 the largest. The tail cylindrical, tapering, covered above with rings 



