REPTILIA. 
161 
JTyla. Two species are described by Prince Max, Nov. Act. Leopold. 
Carol, xxxii. : — S. versicolor j p. 116, and H. triseriaia (Wied, Ileise N. 
Amer. i. p. 249), p. dl8. 
Ilyla aurantiaca. Mr. Cope regards it as the type of a distinct genus, 
Dryomdictes. See above, p. 160. 
llyla yracilipeSf sp. n., Cope, Proc. Ac. Nat. Sc. Philad. 1865, p. 194, 
from the Tableland of Mexico. Ilyla staufferij sp. n., Cope, ibid. p. 195, 
from Orizava. 
Smilisca daulinia is a new generic and specific name given to a skeleton in 
Prof. Hyrtl’s Collection by Mr. Cope. See above, p. 160. 
Pharynyodon, g. n.. Cope, Proc. Ac. Nat. Sc. Philad. 1865, p. 193 ; for cha- 
racters see p. 160. Ph. jidasatm, sp. n., Cope, I c., from Yucatan. 
Zysapsus. Dr. Steindachner has recognized the error in identifying this 
genus with Pscudis minuta, already pointed out by us in Record, vol. i. p. 131. 
Verb. zool.-bot. Gesellsch. Wien, 1865, p. 500. 
BATRACHIA GRADIENTIA. 
Amblystoma and Siredon. M. Aug. Dumeril, in a memoir 
read before the- French Academy of Sciences (Compt. Rend. 
1865, lx. p. 765) has announced the important fact that Axo- 
lotls bred in the tanks of the Reptile-house of the Jardin des 
Plantes. The ova, their attachment to water-plants, and the 
earlier phases of their development are as in the common Newts. 
The spawn was deposited on the 19th and 20th of January, and 
again on the 6th of March ; and the larvfe were hatched twenty- 
eight or thirty days after. They arc, at this stage, 0‘014 or 
0*016 millim. long, and their branchiae consist of three very short 
cylindrical appendages, with comparatively few ramifications. 
The development of the limbs is slow : in examples more than 
two months old no traces of posterior limbs were observed, and 
the anterior had not perceptibly increased in length since the 
tadpoles left the egg-membranes. 
Thus the question whether the Axolotl is a tadpole or a per- 
fectly developed animal was seemingly set at rest, when M. Du- 
meril communicated the startling fact, that nine of the numerous 
young Axolotls bred in Paris had undergone a complete metamor- 
phosis (Compt. Rend. 1865, Ixi. 1865, p.775; and Bull. Soc. d^Ac- 
clim. 1866, February) . In September they had attained to a size 
surpassed by that of the parents by 0 040 or 0*050 millim. only, 
when the external gills commenced to disappear, the form of the 
head changed a little, and the skin became covered with numerous 
white spots. Simultaneously modifications of internal organs 
took place : 1. The hyoid apparatus is simplified, three of the 
internal branchial arches disappear, and the outermost only 
persists. 2. The anterior surface of the centre of the vertebrae 
is more flattened than before the metamorphosis. 3. The vome- 
1865. [vol. II.] M 
