410 Mr. G. A. Boulenger on the 
lateral folds narrow or moderately 
broad, usually with interrupted folds or 
elongate warts between them; outer 
metatarsal tubercle absent or ver y indis- 
tinct; male with external or internal 
vocal BACS AM Cie ioe hie cma R. halecina, L. 
Head as long as broad; interorbital space 
much narrower than upper eyelid; 
dorso-lateral folds very broad, with a 
pair of similar folds between them ; 
outer metatarsal tubercle usually pre- 
sent; male with internal vocal sacs .. J. palustris, Leconte. 
6. Male without vocal sacs. 
Head broader than long; interorbital space 
as broad as or narrower than upper eye- 
lid; tympanum 3 to once-diameter of 
eye; outer metatarsal tubercle absent 
Or very indistinct, nny. smc w aes © . RK. draytonii, B. & G. 
Head as long as broad or slightly broader 
than long ; interorbital space narrower 
than upper eyelid; tympanum 2 to $ 
diameter of eye; a more or less distinct 
outer metatarsal tubercle ............ R. aurora, B. & G. 
2. Web not penetrating beyond basal half of outer metatarsals. 
a. Glandular dorso-lateral fold narrow or moderately broad ; 
head moderately large; vomerine teeth on a level with 
or behind posterior borders of choane. 
Tibio-tarsal articulation reaching tympanum 
or eye; tibia 8 to 45 times as long as 
broad, 2 to 23 times in length from 
snout to vent ; toes ? to nearly entirely 
webbed ; inner metatarsal tubercle 3 to 
2 length of inner toe; male without 
VOCAL BAC o.6s satis pines BOK Se ae R. pretiosa, B. & G. 
Tibio-tarsal articulation reaching tympanum 
or ee tibia 3 to 4 times as long as 
broad, 23 to 25 times in length from snout 
to vent ; toes 4 to 2 webbed ; inner meta- 
tarsal tuber cle 4 to 3 3 length of inner toe ; 5 
male with internal ‘vocal sacs ........ R. cantabrigensis, Baird. 
Tibio-tarsal articulation reaching beyond 
eye; tibia 4 to 5 times as long as broad, 
12 to 2 times in length from snout to 
vent; toes } to # webbed; inner meta- 
tarsal fuberole 2 to 3 length of inner toe ; 
male with internal vocal sacs ........ . silvatica, Leconte. 
b. Glandular dorso-lateral fold broad ; vomerine teeth between 
the choane. 
Head moderate, slightly broader than long, 
3 to 3} times in length to vent; loreal 
