88 OPHIDIA. 
Colobognathus hoffmanni, Peters, MB. Ak. Wiss. Berl. 1859, p. 276, fig. 2; Cope, Bull. U.S. Nat. 
Mus. no. 32, pp. 53, 86 *. 
Geophis hoffmanni, Bocourt, Miss. Se. Mex., Rept. p. 529, t. 31. figg. 8, 8 a-c.' 
Geophidium dubium, Peters, MB. Ak. Wiss. Berl. 1861, p. 923; Cope, Bull. U.S. Nat. Mus. no. 82, 
p. 86. 
? Geophis dubius, Bocourt, Miss. Sc. Mex., Rept. p. 582, t. 31. figg. 9, 9 a-c tT. 
Elapoides sieboldi, Jan, Arch. per la Zool. ii. p. 21 (1862) ; and Iconogr. xii. t. 1. figg. 4. 
Ninia sieboldii, Garman, Mem. Mus. Comp. Zool. Cambr. viii. no. 8, p. 96 (1888). 
Colophrys rhodogaster, Cope, Proc. Ac. N. Se. Phil. 1868, p. 130; and Bull. U. S. Nat. Mus. 
no. 32, p. 86. 
Geophis rhodogaster, Bocourt, Miss. Sc. Mex., Rept. p. 531, t. 31. figg. 12, 12 a-d. 
Geophis fuscus, Fischer, Abhandl. naturw. Ver. Hamburg, ix. p. 11, t. 2. fig. 5 (1886). 
A supraocular and one postocular, sometimes confluent into one scute, sometimes 
one or the other absent. Two pairs of frontals, sometimes confluent into a single pair ; 
the anterior pair, if present, very small ; two pairs of chin-shields. Generally six, 
rarely five, upper labials, the third and fourth entering the orbit, and the fifth in 
contact with the occipital. The first pair of lower labials form a suture together. 
Fifteen or seventeen series of scales, either all being smooth, or only those on the back 
or loin provided with feeble keels; anal entire. Coloration generally uniform black 
above; blackish, yellowish, or whitish below. 
The modifications of this very variable form may be arranged thus :— 
I. Scales in seventeen rows; two pairs of frontals. 
A. Scales keeled. A supraocular and postocular. Ventral scutes 137 or 139. Uniform 
blackish above, yellowish below $. 
Hab. Mexico (Sallé) ; Guarzmata, Duefias and Pacific coast (Salvin). 
B. Scales smooth. A supraocular and postocular.—Catostoma chalybeum (Wagl.). 
Hab. Mexico (Deppe). 
C. Scales smooth. No supraocular; one postocular. Ventral scutes 137 or 142. Uniform 
blackish above, yellowish below.—Colophrys rhodogaster (Cope). 
Hab. Mexico, Yucatan (Smiths. Inst.) ; Guaremata, Rio Chisoy below the town of Cubulco 
(Salvin) ; Costa Rica (Smiths. Inst.). 
* Cope represents this snake as “ without teeth on the palate;” they are distinctly enough shown in the 
figure given by Peters. 
+ Bocourt describes and figures this species with the first pair of infralabials not meeting in the median 
line, whilst Peters expressly states that they meet in front of the chin-shields. The specimens examined by 
myself confirm Peters’ statement, and I am therefore led to suppose that there is some error in Bocourt’s figure 
or in his determination of the specimens. 
+ According to Cope five lower labials are in contact with the chin-shields; I am unable to find more than 
four in any of our specimens. 
§ These specimens would probably have been named Catostoma nasale by Mr. Cope (Proc. Ac. N. Sc. Philad. 
xx. p. 131); but itis rather uncertain what he understood by that name. He describes his specimens as 
possessing eight upper labials, while the figure of the head shows seven only. In the original description quoted 
the specimens are said to be “from near the city of Guatemala,” and in Bull. U.S. Nat. Mus. no. 32, p. 85, 
from “Central Costa Rica.” 
