338 APPENDIX C. — EEPTILES. 



of grayish yellow spread all over the body, head, and tail, remind- 

 ing us of surfaces over which lichens grow, whence the specific 

 name by which we designate this species. 



It was caught by R. H. Kern, Esq., in Spring Lake, at the head 

 of Santa F^ Creek, in New Mexico, accordingly a member of the 

 fauna of the basin of the Rio Grande del Norte. 



In a revision of the North American Tailed Batraehia, published 

 in the Journal of the Academy of Natural Sciences, 2d series, vol. 

 i., p. 281, (1849,) we intimated a doubt as to whether Siredon or 

 the axolotls were adult animals. Their wonderful resemblance to 

 the larvae of Ar)iby stoma punctata was our chief ground for this 

 belief. Since then, however, we have seen the description and 

 figures by Sir Everard Home of S. mexicanus, in which he clearly 

 indicates, in one individual at least, ovaries distended with eggs. 

 We have also seen specimens with the genital apparatus present- 

 ing the tumid and highly developed appearance of salamanders in 

 general, when in the breeding season. 



Cnemidophorus TIGRIS, Baird and Girard. 



PI. II. 



Spec. chab. — Scales on the subguttural fold small in size ; four yellowish, indis- 

 tinct stripes along the dorsal region. 



This species, one of the most elegant of its genus, is the third 

 hitherto described as found in the United States, for we have no 

 doubt that the lizard referred to in Long's expedition, under the 

 name o^Ameiva tesselata, will come under this genus, and be closely 

 allied to our species. No specimen of this being extant at the 

 present time in any known collection, a direct comparison with the 

 other species of Cnemidophorus was not possible. That A. tesselata, 

 however, although closely allied to, is not identical with our species, 

 we think that any one will be convinced on comparing Say's de- 

 scription with the figures in pi. II. These are of natural size, and 

 exhibit most admirably the structure of the regions in their most 

 minute details. The plates of the head above (fig. 3), below (fig. 2), 

 and on the sides (fig. 1), need no further description. The minute 

 scales of the back and upper portion of the legs contrast strikingly 

 with the eight rows of large scales of the belly and those of the 

 lower part of the hind legs, as well as with those of the inferior 

 surface of the head and throat. On the tail again, the scales 

 assume another character, well opposed too; they are longer than 



