AMBLYSTOMATID, — CL Ry 
gills; toes 4-5. Aquatic. Genera 2, species 2. Megalobatrachus 
maximus of Japan and the following. 
a. Spiracles persistent; gill arches4. . . . . . CRYPTOBRANCHUS, 253. 
253. CRYPTOBRANCHUS Leuckart. (kpunrds, concealed ; 
Bpayxos, 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. 
Famity Cl AMBLYSTOMATIDA. (Tue Buiunt-Nosep 
SALAMANDERS.) 
Vertebre amphicelian; 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 larve 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 ee pene teeth extending laterally 
behind inner nares. . . . - . AMBLYSTOMA, 254. 
bb. Folds of tongue radiating i om the mdlian longitudinal furrow; series 
of palatine ‘teeth not extending laterally behind inner nares. 
CuHonprotTus,! 255. 
254. AMBLYSTOMA Tschudi. (auSdvs, blunt ; oroua, mouth.) 
a. Costal grooves 10. 
492. A. talpoideum (Holbrook). Blackish brown, with gray, 
lichen-like markings; tail short, compressed, 24 in length; head 
very broad; body short and squat. Southern, N.to S. Hl. (Lat., 
like a mole, talpa.) 
aa. Costal grooves usually 11. 
6. 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 24 in total length; body stout. L. 34. 
Penn. to Wis., and S. 
ce. 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 
