126 OPHIDIA. 
Drymobius (Eudryas) bodderti (Cope), Bocourt, Miss. Sc. Mex., Rept. p. 720, t. 51. figg. 5,5 a-c. 
Dromicus pleei, Jan, Iconogr. Ophid. xxiv. t. 5. fig. 1 (nec D. & B.). 
Drymobius (Eudryas) pleei, Bocourt, Miss. Sc. Mex., Rept. p. 728, t. 51. figg. 3, 3 a—d. 
Herpetodryas rappii, Salv. P. Z. 8. 1860, p. 456 (nec Ginth.). 
Herpetodryas levis, Fischer, Wiegm. Archiv, 1881, 1. p. 227, t. 11. figg. 4-6. 
Drymobius (Eudryas) levis (Cope), Bocourt, Miss. Sc. Mex., Rept. p. 722, t. 51. figg. 6, 6 a—d. 
Drymobius (Eudryas) dorsalis, Bocourt, loc. cit. p. 724, t. 51. figg. 2, 2 a-d. 
Coryphodon alternatus, Bocourt, Bull. Soc. Philom. 1884, p. 183. 
Hab. Mexico, Tres Marias Is. (orrer), Jalapa, Tuxpan, and Actopam (Cope), Zacualpan 
(H. Finck), Hacienda del Hobo (P. Geddes), Vera Cruz, Huatuzco (H. H. Smith) ; 
GuaTEMALA,. Duefias, low forests of Vera Paz, and Lake Peten (Salvin), Coban 
(Sarg); Nicaracua (Cope); Costa Rica (Smiths. Inst.); Panama (Cope), Veragua 
(Cope).—TropicaL South America; West INDIES. 
As in the majority of isodont Colubrine Snakes, so also in this species the posterior 
teeth are frequently somewhat larger than the middle ones; and this increase in size 
may be in some individuals sufficiently great to lead to the description of the dentition 
as coryphodont. After examining a considerable number of specimens, however, I come 
to the conclusion not to separate such individuals, particularly since I have compared 
specimens from the northernmost as well as the southernmost range, among them such 
as have absolutely the same style of isodont dentition. 
As to the two young specimens from Duefias which were referred to Herpetodryas 
rappw by Mr. Salvin, I believe them now to be the young of H. boddertii, distinct from 
the typical Venezuelan H. rappii. The fact is, that what I considered (Cat. Col. Sn. 
p- 117) a specific peculiarity of H. rappii, viz. the remarkable difference of coloration 
between young and old, is a character common to the majority of these American 
snakes, be they referred to Zamenis, Coryphodon, Drymobius, Herpetodryas, &c. The 
young are ornamented with a series of quadrangular dark cross-bands on the back, with 
which similar spots on the side alternate. If a knowledge of the locality of such a 
young snake does not assist in the determination, it is most difficult, and perhaps 
impossible, to assign it to its proper species. It is aremarkable fact, supported by other 
analogous instances among vertebrates, that this juvenile pattern of coloration may in 
some forms persist throughout the various stages of growth. Thus in specimens from 
Western Ecuador which I have referred as a variety to H. rappii (P. Z.8. 1859, p. 412) 
the quincunciate pattern of coloration remains unchanged with age, but the tints are 
less intense in old than in young individuals. 
3. Drymobius ceruleus. 
Dromicus ceruleus, Fischer, Jahrb, Hamb. Wiss. Anstalt, ii. p. 1038, t. 4. fig. 7 (1885). 
? Drymobius (Eudryas) ceruleus, Bocourt, Miss. Sc. Mex., Rept. p. 727, t. 51. figg. 4, 4 a—d. 
Hab. Guatemata, Coban (Sarg), Vera Paz (Mus. Paris). 
