MEXICAN TAILLESS AMPHIBIANS 



123 



than or subequal with second; fingers and toes quite free, with small 

 but distinct terminal disks; subarticular tubercles very prominent; 

 supernumerary tubercles continued backward on palmar and plantar 

 surfaces; two distinct metatarsal tubercles; the hind limb being carried 

 forward along the body, the tibio-tarsal joint reaches the tympanum 

 or at most to the posterior margin of the eye; head-and-body length, 

 20 to 26.5 mm.; adults probably 25 to 26.8 mm. 

 Specimens examined. — Nine, as follows : 



Tomodactylus nitidus 



' Cotypes of Tomodactylus amulae. 



2 Type of Liuperus nitidtis. 



Genus SYRRHOPHUS Cope 



1878. Syrrhophus Cope, Amer. Nat., vol. 12, no. 4, p. 253, Apr. [Genotype, 

 Syrrhophus marnockii Cope, idem, p. 253 (near San Antonio, Texas).] 



1879. Malachylodes Cope, Proc. Amer. Philos. Soc, vol. 18, no. 104, p. 264, June 

 20. [Genotj'pe, Malachylodes guttilatus Cope, idem, p. 264 (Guanajuato, 

 Mexico).] 



1885. Hypodictyon Cope, Proc. Amer. Philos. Soc, vol. 22, pt. 4, no. 120, p. 383, 

 Apr. 17. [Genotype, Phyllobates ridens Cope, 1866, Proc. Acad. Nat. Sci. 

 Philadelphia, vol. 18, p. 131, May (St. Juan River, Nicaragua).] 



1888. Syrrhopus Boulenger, Proc. Zool. Soc. London, pt. 2, p. 206, Aug. [Emen- 

 dation of Syrrhophus Cope.] 



1900. Syrrhaphus Gunther, Biologia Centrali- Americana, Reptilia and Batrachia, 

 p. 215, Apr. [Emendation of Syrrhophus Cope.] 



Although these small Mexican frogs resemble the young of Eleu- 

 therodadylus, they lack vomerine teeth and have a rounded canthal 

 region with no discernible ridge. The Mexican species do not have 

 a tarsal fold. It would seem that the species of Syrrhophus either are 

 so closely interrelated that the resemblances far outnumber the differ- 

 ences, or else the names available exceed the recognizable species. 

 The specific differences that have been noted seem rather trivial in 

 some instances. One can not be certain from the material at hand 

 whether an areolated condition of the skin has any diagnostic sig- 

 nificance for differentiating the species. With the existing inadequacy 

 of the material it would be difficult to justify the suppression of spe- 

 cific names for which only a single specimen is available or for which 

 the original description is the sole available source of information. 



