64 Dr. Mitchill on the Proteus of Lake Erie. 



individuals of the Ivmnaea heterostropha in the mouth. 

 Within the mouth too was a crustaceous inhabitant, of the 

 oniscus family, a cymothoa with fourteen hooked ieei, and 

 a pair of antennae. Often takes the bait employed to al- 

 lure the silures and other fishes, and is catched by the 

 hook. One of those I possessed was taken in this way. 

 Swims or creeps with a slow and serpentine motion along 

 the bottom, in which he is assisted very much by his broad, 

 compressed and vertical tail. Acquires the length of from 

 12 to 18 inches, or even more. Is often killed by the gig 

 and spear. Though the flesh is white and resembles that 

 of the cat fish and eel, it is never eaten, there being a 

 strong prejudice against it. Under an unfounded opinion 

 that the creature is venomous, it is beheld with a sort of 

 abhorrence, and thrown away. The general appearance 

 is thick, chubby and clumsy. 



Skin slimy, spotted and scaleless. The spots during 

 life resembling those of the brook trout or salmo fontina- 

 lis. The mouth armed with two sets of pointed and some- 

 what curved teeth in the upper jaw, and with one set of 

 similar sharp, uniform and pointed instruments in the lower. 

 Tail surrounded by a skinny film or rim, but without the 

 rays which distinguish the caudal and other fins of fish. 



Four legs, each ending in four toes without claws. 



Three tufts or bunches, appearing to be gills or branchiae 

 on each side of the neck, supported by the three branchial 

 arches, between which there are two openings or slits, ap- 

 parently for the transmission of water. These seem to be 

 respiratory organs ; and as far as the habits and manners of 

 the creature are known, endure through life. 



Two air-sacs, reaching longitudinally from the pharynx or 

 throat, toward the vent, one on each side of the vertebral 

 column ; of such a constitution that ihey may be considered 

 as auxiliary organs of respiration, or as air-bags resembling 

 the vesica natatoria in fishes. 



A persistent tail, flattened laterally, resembling in figure 

 the temporary tails of the tadpoles, or ^;ynm of frogs, and 

 the permanent ones of the Water-Salamanders. 



With all these peculiarities of structure, 1 observed fur- 

 ther that the eyes were small, destitute of lids and covered 

 by the common integuments. Instructed by your commu- 

 nications, and warranted by the near analogy which I 



