ART. 11 NORTH AMERICAN TADPOLES — WRIGHT 27 



average 1.78. Depth of tail 1.9-3.1 in length of tail, average 2.5. 

 Muscular part (4.2-6.4 mm.) 1.75-2.8 in depth of tail (10.0-13.8 mm.), 

 average 2.47, rarely below 2.0. Spiracle 1.5-2.0 nearer base of hind 

 legs or vent region, (5.4-7.G mm.) than the tip of the snout (10.4-12.4 

 mm.), average 1.73, rarely reaching 2.0 or under 1.7. Spiracle 1.0- 

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

 mm.), average 1.18. Eye equidistant, sometimes nearer to tip of 

 snout (4.6-6.0 mm.) than spiracle (5.0-6.0 mm.). Nostril equidistant 

 from snout and eye (2.8-3.6 mm.). Mouth (2.0-3.8 mm.) usually 

 1.1-1.9 larger than internasal space (1.8-3.0 mm.), average 1.72. 

 Mouth contained 1.36-2.0 average 1.62 in interorbital distance 

 (5.0-6.4 mm.). Internasal space contained in interorbital space 

 1.7-2.9, average 2.5, seldom under 2.0. 

 The dimensions of the largest tadpole are: 



Mm. 



Spiracle to vent 7. 6 



Spiracle to eye 5. 4 



Eve to snout 5. 4 



Mm. 



Total length 49. 8 



Body length 16. 6 



Body depth 13. 8 



Body width 12. 6 



Tail length 33. 2 



Tail depth 10. 6 



Musculature of tail 5. 



Spiracle to snout 11. 8 



Eye to nostril 2. 8 



Nostril to snout 2. 8 



Mouth 3.4 



Interorbital distance 5. 



Internasal distance 2. 



RANA BOYLII SIERRAE Camp 



General appearance. — Tadpole fairly large (72 mm.), body flatter 

 than most Ranid tadpoles. It is distinctive in that the tail muscu- 

 lature is wide and keeps the same width for an inch or an inch and 

 one quarter and then suddenly tapers off. Tail very long, tip very 

 bluntly rounded. The crests are broader back near the tail tip than 

 nearer the insertion on the body. The rear half of the tail might 

 be termed elliptical in outline, or the tail tip might tend toward a 

 spatulate tail. The broadest part of the tail comes where the 

 musculature finallj'^ begins to taper. The dorsal crest is very narrow 

 forward and extends on to the body to a vertical twice as near the 

 buds of the hind legs as the spiracle. Spiracle sinistral, below lateral 

 axis, decidedly upturned and somewhat backward in direction, with 

 a prominent round or elliptical pore very evident. 



Anus dextral, opening on a level with the edge of the ventral crest. 

 Muciferous crypts distinct. In preserved material they look like 

 brown or black pigment spots not white as in R. JiecJcsheri or some 

 other Ranid species. On either side of dorsal crest for a distance 

 back of its body insertion there extends a row of crypts which go 

 diagonally outward on the body and finally joins the main dorso- 

 lateral series which starts from the mid-lateral insertion of the tail 

 musculature on the body. This lateral series travels to back of the 



