SIRENID^E. XCVII. 175 



ORDER XXIV. TBACHYSTOMATA. 



This order contains a single family, (rpaxvs, rough ; oro/za, mouth.) 



FAMILY XCVII. SIRENID^J. (THE SIRENS.) 



Body elongated, eel-like, with no' posterior limbs, not even a 

 vestige of pelvis; head flattened; snout obtuse; mouth narrow, 

 jaws with horny sheaths; floor of mouth with teeth or asperities; 

 vomer with two large patches ; eye very small ; lips thick ; tail com- 

 pressed, finned. Genera 2; species 2, Pseudobranchus striatus 

 (LeC.), of Georgia, a small species with 3 toes and with thickened, 

 functionless gills, and the following : 



a. Gills large, bushy, in function throughout life ; toes 4 ; spiracles 3. 



SIKEN, 250. 

 250. SIREN Linnaeus. 



488. S. lacertina L. MUD EEL. Tail shorter than body, 

 pointed at tip. Blackish, sometimes dotted. L. 36. Lowland 

 streams and swamps, N. Ind. to N. C. and S. (Lat., like a 

 lizard.) 



ORDER XXV. PROTEIDA. 

 This order contains a single family. 



FAMILY XCVIII. PROTEIDA. (THE MUD PUPPIES.) 



Salamanders provided with bushy external gills, and having the 

 branchial clefts remaining open through life; teeth well developed; 

 limbs 4. Genera 2 ; species 3 or 4. Proteus inhabits caves in S. 

 W. Austria, and Necturus the fresh waters of the U. S. Proteus 

 is blind, nearly colorless, and has tlje toes 3-2. 



a. Toes 4-4 ; tongue large, free in front ; vomerine teeth in one strong series ; 

 eyes small, not covered NECTURUS, 251. 



251. NECTURUS Rafinesque (1819). (Menobranchus Harlan, 

 1825.) (yr)K.Tr]Si a swimmer; ovpd, tail.) 



489. N. maculosus Rafinesque. MUD PUPPY. (N.) WATER 

 DOG. (S.) Brown, more or less spotted ; young with traces of a 

 lateral band ; gills large and bushy, bright red, forming 3 tufts on 

 each side ; a strong fold across throat ; head broad, depressed ; tail 

 much compressed. E. U. S., chiefly N. and W. of the Alleghanies, 

 abundant in the Great Lake Region. L. 24. (Lat., spotted.) 



ORDER XXVI. URODELA. (THE SALAMANDERS.) 



Body naked, elongate, subterete; both jaws with teeth; 4 limbs 

 present (wanting in the tropical family Caeeiliidae) ; tail persistent 

 through life; no external gills in the normally developed adult. 



