164 OPHIDIA. 
HYDROCALAMUS. 
Hydrocalamus, Cope, Proc. Am. Phil. Soc. xxii. p. 177 (1885). 
1. Hydrocaiamus quinquevittatus. 
Homalopsis quinquevittatus, Dum. & Bibr. Erpét. vil. p. 975. 
Calopisma quinquevittatum, Jan, Iconogr. Ophid. xxx. t. 2. 
Hydrocalamus quinquevittatus, Cope, Proc. Am. Phil. Soc. xxii. p. 176 (1885). 
Hydrops lubricus, Cope, Proc. Ac. N. Se. Phil. 1871, p. 217. 
Hab. Mexico, Coatzacoalcos R., Vera Cruz; GuatemaLa, Peten (Smithson. Inst. ; 
Mus. Paris). 
In spite of the extraordinary similarity of this snake to Tachymenis bipunctata, | 
think it advisable to retain it in a distinct genus. Its physiognomy is entirely distinct 
from the Coronelline type, and is that of a Freshwater Snake—a fact sufficiently recog- 
nized by previous authors who have associated this species with Freshwater genera. 
This feature consists of a short and depressed snout, small eye, and small frontal shields 
(the anterior of which are pointed, the posterior together being about equal in extent 
to the vertical). The occipitals are narrow and elongate. The nasal seems to be 
undivided. 
TOMODON. 
Tomodon, sp.*, Dum. & Bibr. Erpét. vii. p. 932 (1854). 
Manolepis, Cope, Proc. Am. Phil. Soc. xxii. p. 176 (1885). 
Differing from Tachymenis in possessing a large and long grooved tooth. Nasal 
single; anal divided. 
1. Tomodon nasutus. 
Tomodon nasutus, Cope, Proc. Ac. N. Sc. Phil. 1864, p. 166; Sumichrast, Arch. Bibl. Univ. 1873, 
p- 262, and Bull. Soc. Zool. Fr. v. p. 182 (1880). 
Monolepis nasutus, Cope, Proc. Am. Phil. Soc. xxi. p. 176 (1885). 
Hab. Mexico, Colima (Xantus), Tehuantepec (Sumichrast). 
Scales in nineteen series; upper labials eight. Snout projecting, obliquely truncated. 
Brownish, with a blackish-brown band from the neck to the extremity of the tail. 
I have not seen a specimen of this snake. 
CONOPHIS. 
Conophis, Peters, MB. Ak. Wiss. Berl. 1860, p. 519. 
Tomodon, sp., Dum. & Bibr. Erpét. vii. p. 982. 
* Tomodon strigatus, Giinth., described from a specimen labelled “ India,” then believed to come from 
Nicaragua, seems to be, in fact, a South-American snake. (See Boulenger, Ann. & Mag. N. H. 1886, xviii. 
p. 437.) 
