252 ZOOLOGY. 



the entrances of the caves. Its color is a pale reddish white, and, like the 

 fish above mentioned, it is blind, although rudiments of eyes are discover- 

 able under the integuments by dissection ; differing in this respect from 

 the Amhlyopsis spelcpiis, or the blind fish, which has not even rudiments of 

 eves. The body is elongated and slender, the head depressed, but the 

 muzzle rather broad ; the anterior feet are provided with three toes, the 

 posterior with two. The gills are well developed, but, unlike the Axolotl, 

 the opercular fiap is not free, but united to the subjacent integument, so 

 that there are simi)ly the two lateral cervical slits or fissures. It in fact 

 presents a magnified and quite striking likeness to the larva of the 

 American Spekrpcs longicauda, with the exception of the adnate oper- 

 cular flap. The fish-like character is also exhibited in the biconcave 

 vertebrae, which, however, may be produced by the drying up in the 

 prej)ared skeleton of the gelatinous bulb which constitutes the convex 

 articulation of the higher larvae. It is highly probable that Proteus is 

 ovo-viviparous, although the fact has not been distinctly ascertained. 

 Closely related to the Proteus is the genus Necturus, peculiar to North 

 America. The form of this genus is stouter than that of the last, and 

 there are four toes to each foot. Of the three species known, the first, N. 

 lateralis {pi. 88, fg. 2), is an inhabitant of the Mississippi, and the great 

 lakes, Superior, Huron, Michigan, Erie, and Ontario ; the second, N. 

 macxdatus' lives in Lakes George and Champlain ; while the third, N. 

 punctatus, and difl^ering from the others by its uniform markings, is an 

 inhabitant of the Santee River, South Carolina. In common with the 

 Mennpoma, they are termed " alligator," in the central portion of the 

 United States : " salamander" or " water-puppy" in some other districts. 



The genus Siren is also an inhabitant of the United States, being 

 confined, however, to its southern portion. Here, with the external gills 

 of less development than in the preceding genera, the hind legs are 

 entirely wanting, the two anterior being provided with four toes each. 

 The lungs in this genus play a more important part than in the last ; the 

 animal, when in full activity, being obliged to communicate occasionally 

 with the air. One species, -S. lacertina (pi. 88, Jig. 1), attains to a 

 considerable size, and although having the reputation of being venomous, is 

 perfectly free from any power of offence. It is probable that the fossil 

 genus Orthophya, from CEningen, belongs to this fiimily. 



The family of living Menopomidcs, like that of the ProteidcB, is, with a 

 single exception, confined to North America. The branchiae, which are 

 found to exist permanently in the preceding family, here disappear after a 

 certain length of time, leaving a simple perforation on each side of the 

 neck. This, however, is closed up in the genus Megalohatrachus, from 

 Japan. The genus Amphiuma is known by the anguilliform body, I'udi- 

 mentary feet, and pointed head with two parallel series of teeth in the 

 upper jaw. Of the two species known, one having two-toed feet is found 

 generally in the Southern States ; the other, with three toes, occurs in the 

 southern part of the Mississippi valley. Menopoma has a stout, flattened 

 bodv, broad and much depressed head, eyes very minute, skin corrugated 

 456 



