40 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



tinct eyelids. They are oval in outline, the long diameter anteropos- 

 terior. They are widely sei)arateil iroai each other and are not far from 

 the labial border. The jaws arc equal iu front, and the muzzle is per- 

 fectly flat. The upper lii) is not pendulus except at its posterior end, 

 where it is also thick. Tiie free lower lip is decurved, and extends only 

 about one-third the distance round the lower jaw. 



The mouth is wide, and the rictus falls below the posterior canth us 

 of the eye. The inaxillopremaxillary arc of teeth extends to a point a 

 little posterior to a line dropped from the posterior edge of the eye. 

 Tlie vomeropalatine seriivs is quite close to themaxillopremaxillary, and 

 extend about one half way as far posteriorly as the external row. At 

 the n)iddleof tlie arc it sometimes presents a convexity backwards for a 

 short distance. At each o( its extrtmitiesis situated the posterior nostril, 

 which is an oval more or less open, and never a slit, as in the C.fuscus. 

 Its position ditJ'ers from tliat seen in AmpMuma means and Necturus in its 

 being at the end of the row, and not external to it. Theroof of the mouth 

 is everywhere flat. The tongue is wide and is considerably free in Iront, 

 the free border narrowing laterally and posteriorly. It nearly fills the 

 tloor of the mouth, leaving but a narrow space between it and the man- 

 dibular arc. Its surface is thrown into numerous elevated folds, which 

 are thin, and generally anteroposterior iu direction. They intercom- 

 municate by lesser oblique folds, which with other delicate ridges form 

 a net- work between the principal ones. In old specimens or badly-pre- 

 ser^':..! ones the plicfe may be flattened or lowered. 



The legs are quite short; when pressed to the side they are separated 

 by a space equal to 1.25 the length of the anterior limb. The fingers 

 are short and rather free, and the external one is considerably shorter 

 than the internal one. The others are subsequal. An extensive fold 

 of the skin extends from the axilla to near the extremity of the external 

 finger, forming the posterior expanded border of the limb. It is most 

 prominent at the lower part of the upper arm. The posti'rior toes are 

 rather short, and are free from web as to the phalanges. The first is 

 the shortest, and the second a little exceeds the fifth. The third and 

 fourth are subequal, and, with the fifth, are somewhat depressed. This 

 appearance is produced by a dermal wing on the external border, which 

 increases in width from the third to the fifth, becoming very wide on 

 the latter. It continues from the fifth toe on the hinder border of the 

 leg to the base of the thigh, corresponding with the similar fold on the 

 fore leg. The epidermis is not hardened into ungues in this species. 



The skin is perfectly smooth, but is thrown into a longitudinal undu- 

 lating fold on the sides between the fore and hind legs. Th:s fold is 

 obsolete in some specimens, ap])arently on account of the distension of 

 the body with food or eggs. There are a shallow median dorsal groove 

 and fourteen costal grooves. The latter are not distinct on the back or 

 belly, and are best seen on the sides of the latter. The tail has a free 

 dermal border on its superior edge, but none on the inferior edge, thus 



