336 HYLIDJE. 



from the tip of the snout through the eye to the middle of the 

 side ; beneath whitish, immaculate. From snout to vent 2-5 milliin. 

 Great Bear Lake. 



a. 5 . Great Bear Lake. 



Well distinguished from C. triserintus by its shorter hind limbs. 



3. ACRIS. 



Acris, Dam. fy Bib?: viii. p. 506 ; Gilnth. Cat. p. 71 ; Cope, Nat. Hist. 

 Rev. 1865, p. 110, and Journ. Ac. Philad. (2) vi. 1866, p. 86. 



Pupil horizontal. Tongue heart-shaped, free behind. Vomerine 

 teeth. Tympanum indistinct. Fingers free, toes extensively webbed, 

 the tips dilated into very small disks. Outer metatarsals united. 

 Omosternum cartilaginous ; sternum a cartilaginous plate. Diapo- 

 physes of sacral vertebra very slightly dilated. 



North America. 



1. Acris gryllus. 



Acris gryllus, Giinth. Cat. p. 71. 

 Rana gryllus, Leconte, Ann. Lye. N. Y. i. p. 282 ; Harlan, Med. Phys. 



Res. p. 104. 



dorsalis, Harlan, I.e. p. 105. 



Acris gryllus, Dum. §■ Bibr. p. 507 ; Leconte, Proc. Ac. Philad. 1855, 



p. 28. 

 Hylodes gryllus, Ilolhr. I. c. pi. 83. 

 Acris acketa, Baird, Proc. Ac. Philad. 1855, p. 59. 



Habit slender. Vomerine teeth in two oblique groups between 

 the choanse. Head elongate ; snout acuminate, nearly twice as 

 long as the diameter of the eye ; interorbital space as broad as the 

 upper eyelid. First finger a little shorter than second ; toes two- 

 thirds webbed ; subarticular tubercles rather small ; two small 

 metatarsal tubercles. The hind limb being carried forwards along 

 the body, the tibio-tarsal articulation reaches the tip of the snout or a 

 little beyond. Skin smooth or slightly tuberculous, belly granulate. 

 Coloration very variable ; generally a large triangular dark -brown 

 spot between the eyes ; sometimes a light dorsal baud. Male with 

 a sugbular vocal sac. 



United States : the typical form confined to the Austro-riparian 

 region, the var. crepitans to the Eastern and Central regions. 



a. Hgr. South Carolina. Dr. Harlan [P.]. (As typical 



of Sana dorsalis.) 

 b-c. $ & hgr. South Carolina. y 



d. Many spec. : rf, N.America. Edward Doubleday, Esq. [P.]. 



?,&hgr. 



Var. crepitans. 



Hylodes gryllus, Delay, New York Faun., Rept. p. 70, pi. 22. 

 Acris crepitans, Baird, Proc. Ac. Philad. 1855, p. 59 ; Leconte, eod. 



