386 REPTILIA. 



as these animals [Anvphivma and Menopomct] are a degree nearer fish, 

 these arteries are each again subdivided into two, which afterwards 

 wind round those singular parts — in some measure similar to the gills 

 of fish, — with which they are furnished. Having made this circuit, the 

 subdivided vessels again unite so far as to form only two trunks, and 

 these two presently join into one in the same manner as we have 

 remarked in turtle and fish. 



The other animal — the siren — completes the gradation by being one 

 remove nearer to fish : in this the subdivision is not into two branches 

 only, as in that above described, but the whole aorta divides and sub- 

 divides into infinite ramifications, similar to the artery in the gills of 

 fish, while the lungs are supplied in the same manner as those of the 

 preceding animal and of the Amphibia. 



Thus the gradation is formed from perfect lungs, first to perfect 

 lungs and imperfect gills, then to perfect lungs and perfect gills, till at 

 last we have no lungs, but simply perfect gills, as in the fish. 



The Chuah Chisstannah, or Craw-fish Eater [Menopoma 

 Alleghaniense, Harlan] . 



This animal may be said to be the third link in the chain between 

 the fish or Dicoilia, and the Tricoilia. It is a quadruped, and is pecu- 

 liar to some of the inland waters ; but is scarce in the rivers, and is 

 seldom caught except when the Indians fox [stupify] the fish with 

 buck-eye roots, made into a paste. 



The colour, when first taken out of the water, is a dark brown on 

 the back, and on the belly a faint yellow ; the skin is without scales and 

 slime. The body is long, with a protuberance on each side of the back, 

 which forms a hollow that extends to the root of the tail : on the sides 

 of the body there is a loose skin, which they can extend or contract at 

 pleasure, to swim with ; and when out of the water it appears like a 

 furled sail. 



They live but a short time on land, and appear almost motionless till 

 disturbed ; and their actions then are like those of a rattlesnake when 

 much fatigued by long teazing. Their bite is sharp, and they will 

 seldom quit their hold till compelled. It is somewhat like a frog elon- 

 gated, being about 7 or 8 inches from the tip of the mouth to the 

 posterior part, or joining of the hind legs ; but this will depend on the 

 size of the animal. 



It is flat on the back and belly like a lizard ; it has four short thick 

 legs ; its feet are broad with four short toes on each fore-foot, and five 

 toes on each hind-foot. 



