1852.] 125 
of the Journal, of late Nos. of the Proceedings, and of previous Nos. 
of the same, deficient in the series of that Society. 
August 24th. 
Prof. HALDEMAN in the Chair. 
Letters were read : 
From Lieut. W. 8. Boyd, U. S. Marine Corps, dated Valparaiso, 
June 27th, 1852, referring to a collection of shells now offered for sale 
by Mr. Weld, Purser U. S. N. 
From Prof. Ehrlich, dated Linez, April 3, 1852, presenting the works 
announced this evening. 
From M. Laporte, Sr., dated Bordeaux, May 4, 1852, in reference 
to an exchange of foreign insects for those of this country. 
August 31st. 
Mr. Orp, President, in the Chair. 
The Committee on the following paper by Prof. Baird and Mr. Chas. 
Girard, reported in favor of publication in the Proceedings. 
Characteristics of some New Reptiles in the Museum of the Smithsonian 
Institution. 
By Srencer F. Bairp and Cuarres Girarp. 
SECOND PART, 
Containing the species of the Saurian order, collected by John H. Clark, under 
Col. J. D. Graham, head of the Scientific Corps U. 8. and Mexican Boundary 
Commission, and a few others from the same or adjoining territories, obtained 
from other sources, and mentioned under their special headings. 
Hortsroonia Texana, B. and G.—Cophosaurus texanus, Trosch. Arch. fur 
Naturg. for 1850, (published in 1852,) 389. Tab. VI. 
This species, easily distinguished from H. maculata, attains a larger size and 
is provided with a more elongated tail. The body above and the lower surface 
of the head are grayish, maculated with small yellowish white subcircular dots ; 
on the upper surface of the tai] and hind legs there are transverse bands of black. 
On the posterior half of the abdomen there are two black crescents, the convexity 
of which is posterior, and extending from near the back to the belly, without 
coming into contact either above or below. ‘The space between the crescents, 
as well as an anterior and posterior area, are yellowish white on the back and 
blue on the belly. The breast, the medial line of the belly, the inferior surface 
of thighs and tail, are unicolor, of a uniform yellowish white ; the tail underneath 
presents seven or more large subquadrangular or subcircular black patches. In 
the female, the abdominal crescents are represented by two lateral spots. 
Localities.—Along the Rio San Pedro, a tributary of the Rio Grande del Norte. 
HoLBroonia AFFINIS, B. and G.—This species comes nearest to H. tezana, 
from which however it can be readily distinguished by its more slender form and 
its proportionally larger dorsal scales and superciliary plates. The coloration 
differs but little from the former in the female, to which sex the only specimen 
in our possession belongs. ‘The back however is darker, scattered with black 
spots, of which two dorsal rows may be followed from the occiput to the base of 
the tail, where they meet and constitute a crescent or an angle, the convexity of 
