AMBLYSTOMATID.E. — CI. 1 77 



gills; toes 4-5. Aquatic. Genera 2, species 2. Megalobatrachus 



maximus of Japan and the following. 



a. Spiracles persistent; gill arches 4 Cryptobranchus, 253. 



253. CRYPTOBRANCHUS Leuckart. (kpvtttos, concealed ; 



Ppdyxos, gill.) 



491. C. alleghaniensis (Daudin). Hellbender. Blackish; 

 side of body with a thick fold of skin. L. 24. Ohio Valley and 

 S., a very unprepossessing but harmless creature. Var. fuscus 

 Holbr., brown, paler below, occurs in Tenn. R. 



Family CI. AMBLYSTOMATID^J. (The Blunt-nosed 



Salamanders.) 



Vertebral amphicoelian ; carpus and tarsus ossified ; toes 4-5, 

 not webbed ; tongue thick ; a band of teeth across posterior part 

 of vomer; no teeth on parasphenoids (behind vomer). Genera 6 ; 

 species about 25, mostly North American. The larva; of A mblystoma 

 often reach a large size before the gills disappear, and sometimes 

 breed while in this condition. These were formerly considered 

 as forming a separate genus, Siredon, supposed to be allied to Nec- 

 turus. 



a. Tongue sub-circular, with radiating folds, its lateral borders free ; palatine 

 teeth in a long series, continuous or interrupted; tail compressed; mucous 

 pores before i 

 b. Folds of tongue radiating from behind; palatine teeth extending laterally 



behind inner nares Amblystoma, 254. 



bb. Folds of tongue radiating from the median longitudinal furrow; series 

 of palatine teeth not extending laterally behind inner nares. 



Ciiosdrotus, 1 255. 



254. AMBLYSTOMA Tschudi. (dufikvs, blunt ; arropa, mouth.) 



a. Costal grooves 10. 



492. A. talpoideum (Holbrook). Blackish brown, with gray, 

 lichen-like markings; tail short, compressed, 2-J in length; head 

 very broad ; body short and squat. Southern, X. to S. 111. (Lat., 

 like a mole, ta/pa.) 



aa. Costal grooves usually 11. 

 b. Sole with one indistinct tubercle, or none. 

 c. Body with gray cross-shades. 



493. A. opacum (Gravenhorst). Black above, with about 14 

 bluish gray bars; belly dark blue; no dorsal furrow; no enlarged 

 pores on the head; tail 2\ in total length; body stout. L. 3^. 

 Penn. to Wis., and S. 



cc. Body with yellowish spots. 



1 The essential character of this genus lies in the osteology of the tongue and hyoi<l 

 bones, and cannot easily be explained without figures. See Cope, Amer. Nat., 1887. 



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