AMPHIBIANS AND REPTILES. 47 
Ambystoma tigrinum (Green). 
PLATE 6. 
Tiger Salamander. ‘Tiger Triton. 
Head 6; depth 8% ; width of head 1% in its length from snout 
to gular fold; length of mouth, or gape, 134; interorbital space, 
measured from eye-sockets, 31%; width of mouth 124; fore limb 
about 1; hind limb a little more than head; tail 114 in rest of 
body. Body stout, rather thick, of massive appearance. Surface 
akore 
4 eo 
Tiger Salamander. Ambystoma tigrinum (Green). 
all rounded, smooth and convex. Trunk swollen, large, slightly 
depressed. Costal grooves 13, counting inguinal, and about 4 
or 5 well-developed pelvic grooves. Scapular groove also evident. 
Grooves on tail at first more or less evident but becoming obso- 
lete posteriorly. Tail rather long, subquadrate at base, its width 
at that point 44 its depth, immediately becomes oval in cross- 
section with bulge above, and posteriorly more or less decidedly 
compressed for a good space to its tip. ‘Tail with upper and 
lower surfaces more or less keeled to tip, though about terminal 
third of its length sharp both above and below. ‘Tip with an 
