AMBLYSTOMATID^. — CI. 177 



gills; toes 4-5. Aquatic. Genera 2, species 2. Mer/alobatracJius 



maximus of Japan and the following. 



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



253. CRYPTOBKANCHUS Leuckart. (/cpwror, concealed; 



^pdyxos, 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. AMBLYSTOMAMD^. (The Blunt-nosed 

 Salamanders.) 



Vertebra? 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 Ambi.ystoma, 2.54. 



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

 of palatine teeth not extending laterally behind inner nares. 



Chondrotus,^ 255. 



254. AMBijYSTOMA Tschudi. (a)ui3Xu?, blunt; oro/ita, 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.) 



aa. Costal grooves usuallj- 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 ; tall 2i in total length ; body stout. L. 3^. 

 Penn. to Wis., and S. 



cc. Body with yellowish spots. 



1 Chondrotus ia not fouud within our limits, and should be omitted. 

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