D PROCEEDINGS OF THE NATIONAL MUSEUM vol 74 



el. Labial teeth |; tadpoles 49-72 mm. in length; dorsal crest very high extend- 

 ing to vertical of the spiracle {Rana sylvatica) or tail broader nearer its 

 tip than at its body insertion, rounded, spatulate, or elliptical {R. boylii 

 sierrae); upper fringe of teeth about 1.5 times the length of the horny beak. 



/'. Tadpole to 49 mm.; dorsal crest very high, extends on to the body to vertical 

 of the spiracle; tail tip acuminate; tail musculature begins to taper at once; 

 dorsal crest higher in cephalic half; depth of tail in length of tail 1.9-3.1, 

 average 2.5; spiracle 1.5-2.0 nearer base of hind legs or vent than tip of 

 snout, average 1.75; nostril to snout erjuidistant to nostril to eye; internasal 

 space in interorbital space 1.7-2.9, average 2.5; depth of body 1.08-1.23 

 in body width, average 1.14; depth of body 1.66-2.0 in body length, average 

 1.78; second upper lateral row about f of the upi^er fringe of teeth; the 

 median space between the lateral portions of this second row 0.4-0.8 times 

 either lateral portion; the third upper row is ^ to f of the upper fringe; 

 fourth lower row of teeth is tt to tt of the first lower row; spiracle 1.0-1.48 

 nearer eye (5.0-6.0 mm.) than base of hind legs or vent (5.4-7.6 mm.). 

 Egg mass submerged, globular. 

 Ontario-Nova Scotia, south to South Carolina. (PI. 3, fig. 5.) 



Rana sylvatica. 



p. Tadpole to 72 ram.; dorsal crest low extending on to body to a vertical twice 

 nearer hind legs than spiracle; tail tip rounded, elliptical or spatulate; 

 tail musculature for an inch or more does not taper; dorsal crest narrow in 

 cephalic half; depth of tail in length of tail 2.5-5.7, average 4.0; depth of 

 body 1.1-1.8 in body width, average 1.43; depth of body in body length 

 2.0-3.0, average 2.325; spiracle 1.0-1.33 nearer base of hind legs or vent than 

 tip of snout, average 1.17; spiracle 1.45-2.375 nearer eye (4.0-8.0 mm.) 

 than base of hind legs or vent (5.8-12.0 mm.), average 2.05; young tadpoles 

 occasionally with teeth f rarely |; nostril 1.0-1.75 nearer the eye than 

 snout; internasal space 1.3-2.0 in interorbital space, average 1.5; second 

 upper lateral row \ to f of the upper fringe; median space between lateral 

 portions of second upper row 1.0-2.3 times either lateral part; the third upper 

 row is \ to T5 of the upper fringe; the fourth lower row of teeth is ^ to i 

 of the first lower row. (PI. 3, fig. 4.) Rana boylii sierrae. 



e*. Labial teeth ^ occasionally f rarely \; tadpoles 74-150 mm. in length; 

 dorsal crest not extending to vertical of the spiracle, but usually just ahead 

 of the buds of the hind legs; tail always elliptical not spatulate; upper 

 fringe of teeth equal to or slightly larger (never 1.5 times) the horny beak. 



/*. Tadpoles 74-84 mm.; tadpoles usually transform the same season they are 

 born; transformation sizes 18-30 mm. average 24 mm. (except R. aesopus); 

 tadpoles (except in R. aesopus) not strongly pigmented on belly, viscera 

 plainly showing through skin (in spirit specimens) . 

 Egg mass globular or plinthlike beneath surface of water. 



gK Body in tail 2.15-2.85, average 2.6; depth of tail in length of taU 2.6-3.5, 

 average 3.0; nostril 1.0-1.5 nearer eye than snout, average 1.25; eye 1.0-1.3 

 nearer spiracle than snout, average 1.12; median space between the second 

 upper labial row 1.0-2.0 times the length of either lateral part of this row; 

 third lower row 0.33-0.66 shorter than the first or second rows; tail covered 

 with large prominent dark spots; belly strongly pigmented, in spirits it 

 looks white, viscera not visible. 

 South CaroHna-Florida-Louisiana (Viosca). (PI. 2, fig. 4.) --Rana aesopus. 



g^. Body in tail 1.3-2.2, averages (1.53, 1.6, 1.7); depth of tail in length of tail 

 2.3-3.4, averages 2.7, 2.65, 3.0; belly not strongly pigmented, in spirits 

 dark, viscera show through the skin. 



