54 Trans. Acad. Sci. of St. Louh. 



(radius and ulna, tibia and fibula), metapodials (carpals and meta- 

 carpals, tarsals and metatarsals), and digits (phalanges); heart with 

 three cliambers; internal nares; respiration, at least during part of 

 life, by means of gills; skin naked. Young, usually after leaving egg, 

 undergoes a metamorphosis. (Stejneger.) 



TMs class includes three recent orders, namelj'', the 

 Caecilians (Apoda), the Salamanders (Caudata), and the 

 Frogs (Salientia). Of these only the two latter orders 

 are represented within our present limits. 



Order CAUDATA. 



Amphibia having a lizard-like, eel-like, or serpent-like form. At least 

 the fore limbs and the shoulder girdle are present in all forms; and 

 usually also the hind limbs. Posterior limbs never conspicuously larger 

 than the anterior. Proximal elements of the tarsus not elongated. 

 Vertebrae numerous, at least 14 in front of the sacrum; these either 

 amphicoelous or opisthocoelous. Ribs present, short. Maxilla present 

 in all, except Necturus and Siren. Teeth present on maxillaries, vomero- 

 palatines. and on the dentaries, except in Siren. No tympanic cavities 

 or eustachian tubes. Cloaca opening externally by a longitudinal slit. 

 (Hay.) 



This order is divided into three suborders, viz., the 

 Mudpuppies (Proteida), the Sirens (Meantes), and the 

 true Salamanders (Mutabilia). 



So far nineteen species have been found in Missouri. 



Suborder PROTEIDA. 



The suborder Proteida may be defined as follows: No median sternal 

 elements. Vertebrae amphicoelous. Carpus and tarsus cartilaginous. 

 Inner walls of vestibule osseous. Nasalia wanting. Teeth on all the 

 usual bones except the maxillaries, which are wanting. The second 

 ceratobranchial is generally present, as in Mutabilia. Stapes directly 

 connected v;ith the suspensorium. (Cope.) 



Of this suborder but three genera are known, Necturiis 

 and TypJilomolge of North America, and Proteus of 

 Europe. 



Genus nectueus. 



Vomero-palatine teeth in a single series. Three persistent branchial 

 arches. Tongue large and fleshy, free in front and on the sides. Eyes 

 small and distinct. Vertebrae amphicoelous. Carpus and tarsus carti- 

 laginous. Head elongate. Trunk short, thick. Fingers and toes four. 



