52 REPORT OF NEW JERSEY STATE MUSEUM. 
Key to the genera. 
a, PLETHODONTIN#. ‘Tongue attached by a band extending from its central 
or posterior pedicel to the anterior margin. 
b. Toes 4—4. HEMIDACTYLIUM 
bb. Toes 4—5. PLETHODON 
aa. SPELERPIN#. ‘Tongue free all around, attached by its central pedicel only. 
c. Two premaxillary bones, with fontanel. GYRINOPHILUS 
cc. One premaxillary bone, with fontanel. SPELERPES 
Genus Hremipactyiium Bonaparte. 
The Four Toed Salamanders. 
Hemidactylium scutatum Tschudi. 
PLATE 8. 
Four Toed Salamander. Hemidactylium scutatum Tschudi. 
Four Toed Salamander. 
Head 714; depth about 14%4; width of head about 13% in its 
length from snout to gular fold; length of mouth, or gape, about 
1°/,; interorbital space, measured from eye-sockets, about 3%; 
width of mouth 124; fore limb about 1%; hind limb about 1%; 
head and trunk about 1% in tail. Body rather robust, elongate, 
more or less depressed below anteriorly, and rounded convexly 
above. Surface all rounded, smooth and convex. Trunk not 
swollen, convex above, and somewhat depressed below. Costal 
grooves 13, counting axillary and inguinal, well-marked, and 
more or less continued over abdomen. At an acute angle pro- 
ceeding backwards from dorsal line are grooves corresponding 
in number and uniting with lines directed at less acute angle from 
upper ends of costal grooves. A rather obsolete longitudinal 
