6 Expedition to the 



The northwestern slope of that range of mountains, known 

 collectively as the Alleghanies, has a moderate inclination 

 towards the bed of the Ohio, and the St. Lawrence, which 

 run nearly in opposite directions along its base. This moun- 



ed by the character of the persistent branchia, than it is to the well known 

 types of the genus, of which the branchia disappear at the age of puberty. 

 Of such animals the following may be instanced: 



The Axolotl of Mexico. Siren pisciformis of Shaw. Gen. Zool. 



The Tetradnctyla of Lacepede in the Ann. des. Mus. Vol. 10. 



The Siren Operculee of Beauvois in Philos. Trans, of Phila. Vol. 4. 



And possibly also, the Proteus JV*eo Ccesariensis of Professor Green — 

 Jour. A.N. S. Vol. 1. 



These four or five species might with propriety be separated from the 

 genus to which they are referrible in the present state of the system, and 

 placed in a separate genus, the external characters of which will be the 

 same as those of Triton, with the exception of the persistent branchia. 

 Its proper station will doubtless be intermediate between Triton and Pro- 

 teus, but far more closely related to the former. 



It may be proper to mention in this place, that the generic name Tri- 

 ton, was applied by Laurenli to the Newts, long before Montfort made 

 use of it in Conchology to designate the war conch of the ancient Ro- 

 mans, and of the present inhabitants of Madison's island. 



We are indebted to Dr. Richard Harlan, for the following anatomical 

 observations, on this singular animal. 



Alveolar margins of the maxilla? serrated, the spiculae pointing back- 

 wards towards the esophagus. The esophagus very large, like that of the 

 serpents, gradually expanding as it descends to form the stomach, which 

 again contracts at the commencement of the intestinal tube; the lining 

 membrane of the esophagus and stomach, thrown into longitudinal folds, 

 which were continued throughout the intestines; which tube undergoes 

 several enlargements in its course, giving it a sacculated appearance si- 

 milar to the alimentary canal of the alligator: in the animal under consi- 

 deration, they form several convolutions previous to their termination into 

 the cloaca; the stomach contaiued an earth worm. The mesentery transpa- 

 rent, displaying a number of very large lacteals, which in the present in- 

 stance, were filled with coagulated chyle. Length of the intestines 10 in- 

 ches. The ovary is of considerable size, of an oblong figure, lying close to 

 the vertebrae, and opening by a straight duct into the posterior part of the 

 cloaca. Liver very large, and apparently (but not certainly) discharged its 

 contents into the stomach. Lungs, consist of two long membranous bags, 

 which run the whole length of the abdomen, anteriorly to the stomach and 

 intestines; the opening of the larynx scarcely large enough to admit a 

 pin's head; the lungs resemble two long air bags, more than a true pulmo- 

 nary apparatus; the cartilaginous laminae of the branchia, three in num- 

 ber, attached superiorly to the integuments over the cervical vertebrae, 

 converging together beneath or anteriorly, and are attached to a cartilage, 

 answering to the os hyoides; the heart, which was extremely small, con- 

 sisted apparently of one auricle, and one ventricle, the aorta soon bifur- 

 cated, sending one branch to each pulmonary apparatus to be intimately 

 ramified upon the branchia, resembling so far the circulation of fishes, and 



