MEXICAN TAILLESS AMPHIBIANS 



179 



into the air, immediately spread out its limbs, and sail slowly down in fine style, 

 passing far over my head and landing at a spot 90 feet behind me. It was quite 

 uninjured. (There was a slight breeze blowing at the time in the same direction 

 toward which the frog glided, but not enough, I fancy, to account for more than 

 a few yards of lateral movement.) 



The experiment was repeated, and it was found that the frog took 7% seconds 

 to reach the ground. On this occasion I was at the top of the tower, and was able 

 to observe that after it had dropped the first 12 feet up [sic] or so, there was, 

 apparently, no further acceleration in the speed of descent; for at this point a 

 state of equilibrium is reached in which the upward pressure of the air on the 

 ventral surface of the frog is equal to the animal's weight. 



Specimens examined. — Nineteen, as follows : 



Hyla venulosa 



Museum 



M.C.Z.-.- 

 U.S.N.M.. 



Do 



B.M 



Do 



A.M.N.H. 



M.C.Z 



B.M 



U.S.N.M.. 

 Do.-. 



A.M.N.H. 



Do.-.- 

 B.M 



Do.... 



Catalogue 



No. 



8375 



38264 



38303 



56.3.17.24 



81.10.31.20 



6300 



9761 

 54. 11. 13. 

 14-17 

 46829 

 46917 



13449 



13841 



57.10.28.49 



59. 9. 20. 2 



Num- 

 ber of 

 speci- 

 mens 



Locality collected 



Vera Crtjz: 



Cerro del Qallo 



Cordoba 



;""]do"-i"iii"i'iiii""i^ii! 



Jalapa 



One mile south of New 



Cemetery. 

 Panuco 



No definite locality 



1 Nayarit: Santa Teresa. 



1 Oaxaca: Tuxtepec 



I ?State: 

 1 t No definite locality... 



1 I do... -.- 



2 do 



2 do 



Date collected 



1921 

 Mar. 21, 1908 

 Mar. 25, 1908 



June 16,1919 

 Apr. 10,1923 



Aug. 9, 1897 

 Apr. 11,1894 



By whom collected or 

 from whom received 



E. R. Dunn. 

 Frederick Knab. 



Do. 

 Auguste Sallf. 

 C. T. Hoege. 

 Paul D. R. Ruthling. 



W. W. Brown. 

 Hugh Cuming. 



Nelson and Goldman. 

 Do. 



PaulD.R.Ruthling. 



. Do. 



E. Parzudaki. 



> Cotypes of Hyla lichenosa. ' Cotypes of Hyla nigTopundaia. 



Genus HYLELLA Reinhardt and Liitken 



1862. Hylella Reinhardt and Ltjtken, Vidensk. Meddel. Nat. Forening, 1861, 

 Kj0benhavn, pt. 1, p. 199. [Included species: Hylella tenera Reinhardt and 

 LtJTKEN, idem, p. 200; and Hylella pundatissima Reinhardt and Ltjtken, 

 idem, p. 200, pi. 4, fig. 5 (from vicinity of Lagoa Santa, Brazil).] 



1879. Exerodonta Brocchi, Bull. Soc. Philom. Paris, ser. 7, vol. 3, p. 20. [Geno- 

 type, Exerodonta sumichrasti Brocchi, idem, p. 20 (Santa Efigenia, Mexico) .] 



Two species of Hylella are known to occur in Mexico, and they 

 differ from all other Mexican Hyhdae in the absence of vomerine 

 teeth. These diminutive tree frogs must escape the notice of collec- 

 tors, since they are rarely found in collections made in that country. 

 Very few specimens of either of these species have thus far found 

 their way into American museums. The eastern form, Hylella pida, 

 is the most distinctively marked of the two Mexican species. The 

 presence or absence of vomerine teeth in the young of some species of 

 Hyla is sometimes difficult to determine without dissection, and they 

 occasionally may be confused mth adult Hylella. 



