AMBLYSTOMATIM. CI. 177 



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



maximus of Japan and the following. 



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



253. CRYFTOBRANCHTJS Leuckart. Opwrroy, concealed; 



Ppdy X os, gill.) 



491. C. alleganiensis (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. AMBLYSTOMATIDuSJ. (THE BLUNT-NOSED 



SALAMANDERS.) 



Vertebraa 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 Amblystoma 

 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. 



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

 of palatine teeth not extending laterally behind inner nares. 



CnoNDROTUS, 1 255. 



254. AMBLYSTOMA Tschudi. (dftjSAvy, blunt ; o-rd/za, 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, tal-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 Chondrotus is not found within our limits, and should be omitted. 

 12 



