1879.] ^ Q% ' [Cope. 



Choanse and ostia pharyngea small and equal ; tongue obpyriform and en- 

 tire. The digital dilatations are small, and the inferior tuhercles of the 

 digits are well marked both anteriorly and posteriorly. A large palmar 

 tubercle ; solar tubercles weak. The hind foot is rather slender, the solar 

 part equaling the tibia in length. Skin everywhere smooth. 



All the superior surfaces, including limbs, a dark mulberry-brown, dot- 

 ted with moderately large gray spots ; below a pale pinkish-brown (in 

 spirits), without markings. Lores and upper lip like the back. 



Length of head and body, .024 ; of head to angle of jaws (axial), .008 ; 

 width of head at angle of jaws, .009 ; length of hind limb, .035 ; of hind 

 foot, .010. 



From Santa Efigenia. No. 10040 (No. 14). Found in woods. Accord- 

 ing to Mr. Sumichrast, the dorsal spots are yellow in life. 



18. Cystignathus melanonoius Hallow. 



19. Cystignathus perlmvis, sp. nov. 



The species of this genus are numerous, and difficult to distinguish. 

 They fall naturally into groups defined by the form of the series of vomer- 

 ine teeth, and the presence or absence of a discoidal fold of the abdominal 

 integument, and of membranous margins to the posterior digits. The 

 latter character does not suffice for the discrimination of a genus, hence 

 I regard Tarsopterus R. & L. as synonymous with Cystignatlius. 



The species of the Mexican district of the Neotropical Realm all have a 

 discoidal abdominal fold, and the vomerine teeth in short transverse series 

 behind the line of the posterior boundary of the choanse. I know but one 

 species which has dermal digital margins. The species are distinguished 

 as follows. I premise that the presence or absence of spots is not con- 

 stant among them : 



I. Posterior digits with dermal margins. 



Dermal glandular folds numerous, generally broken up ; legs stout, heel 

 reaching orbit ; tympanic membrane .66 of eye ; no light stripe on 

 lip C. melanonoius. 



II. No digital dermal margins. 



No glandular folds ; legs slender, heel reaching front of orbit ; tympanum 



.66 of orbit ; no light lip stripe C. perlavis. 



Glandular folds (?) none ; legs very robust : heel reaching orbit ; tympanum 



.4 of orbit ; no stripe on lip C. microtis. 



Glandular folds present ; legs short, reaching orbit ; tympanum equal or- 

 bit ; lip stripe imperfect C. gracilis. 



Glandular folds; legs long, reaching front of orbit ; tympanum .6 of orbit; 



a lip stripe C. labialis. 



The C. perlmvis is characterized by its exceedingly smooth and shining 

 skin, which is entirely without the glandular ridges usual in the genus. 

 The head is angular oval in outline with distinct canthus rostrales, which 

 are near together, and much within the labial outline. The muzzle pro- 

 jects a little, and the nares are about one-third the distance from its apex 

 to the orbit. Tongue a longitudinal oval, entire behind ; choanal rather 



PROC. AMER. PHILOS. SOC. XVIII. 104. 2l. PRINTED AUGUST 11, 1879. 



