AMBLYSTOM ATID^E. CL 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. (Kpvirros, concealed; 



fipdyxos, 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 CL AMBLYSTOMATID^El. (THE BLUNT-NOSED 

 SALAMANDERS.) 



Vertebrae 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 larvae 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 eye. 



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

 behind inner nares ........... AMBLYSTOMA, 254. 



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

 of palatine teeth not extending laterally behind inner nares. 



254. AMBLYSTOMA Tschudi. (a/i/3Xuf, blunt ; oro>a, mouth.) 



a. Costal grooves 10. 



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

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

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

 like a mole, talpa.) 



an. 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 hyoid 

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



12 



