70 Trans. Acad. Sci. of St. Louis. 



thing, but still when I killed them they were plump and 

 fat. 



Congo Snakes are remarkable for the size of their blood 

 corpuscles, the largest furnished by any vertebrate, being 

 visible to the naked eye. The number of their vertebrae 

 is also worthy of remark, there being altogether about 110, 

 of which 65 lie in front of the sacrum. (Hay.) 



Family Cryptobranchidae. 



Form salamandrine. Head broad and depressed, mouth wide. Limbs 

 four, well-developed. Tail broad and compressed. Teeth on the ante- 

 rior edge of vomers, concentric with those of the premaxillaries and 

 maxillaries, but not extending so far back as the latter. No teeth 

 on parasphenoids. Tongue large, free in front. (Hay.) 



This family embraces three genera, Proteocordylus 

 (Andrlas), known only from the Miocene of western 

 Europe, Cryptobranclms, which only occurs in eastern 

 North America, and Meg alobatrachus , known from Japan 

 and China. (Stejneger.) 



4. Crytobranchus alleghaniensis Daudin. Hellbender. 

 Mud-Devil. 



Salamandra alleghaniensis, Salaviandra gigantea, Protonopsis horrida, 

 Abranchus alleghaniensis, Salamander des monts alleghaniens, 

 Menopoma alleghaniensis, Cryptobranchus horridus, Menopoma 

 alleghaniense. 



Description. — Size large, body heavy and depressed. Head broad and 

 flat and snout rounded. Tail broad and much depressed, with a fin 

 along its upper edge; its length equal to half the remainder of the 

 animal. Skin richly provided with mucous follicles, especially about 

 the head. Sides with a conspicuous, corrugated cutaneous fold, which 

 extends from the angle of the mouth to the middle of the tail. 



Mouth large, the gape extending to behind the eyes. Nostrils small, 

 close to the edge of the lips. Eyes small, with no evident lids. Limbs 

 short and stout, bordered externally by a fold of membrane, which 

 extends down to the outer toe. Hind limbs stoutest, and bordered 

 behind by a second fold, which, near the foot, passes into the external 

 fold. Digits 4-5. The distance from the snout to the gill-slit is equal 

 to about one-sixth or nearly one-seventh of the total length. (Hay.) 



Color. — The usual color is a rather light lead to yellowish clay, 

 paler beneath. Some specimens, particularly the younger ones, have 



