HYDROMORPHUS.—HYPSIGLENA. 187 
HYDROMORPHUS. 
Hydromorphus, Peters, MB. Ak. Wiss. Berl. 1859, p. 276. 
1. Hydromorphus concolor. 
Hydromorphus concolor, Peters, loc. cit. p. 277, fig. 3 (head and dentition). 
Hab. Costa Rica (Hoffmann). 
HYPSIGLENA. 
Hypsiglena, Cope, Proc. Ac. N. Sc. Phil. 1861 (1860), p. 246. 
Pseudodipsas, Peters, MB. Ak. Wiss. Berl. 1861 (1860), p. 251. 
1. Hypsiglena torquata. 
Leptodeira torquata, Giinth. Ann. & Mag. N. H. (3) vy. p. 170, t. 10. fig. A (Febr. 1860). 
Hypsiglena torquata, Cope, Bull. U.S. Nat. Mus. no. 32, p. 78. 
Hypsiglena ochrorhynchus, Cope, Proc. Ac. N. Se. Phil. xii. p. 246 (June 1860). 
Comastes quincunciatus, Jan, Iconogr. Ophid. xxxviii. t. 1. fig. 1. 
Hypsiglena chlorophea, Cope, Proc. Ac. N. Sc. Phil. xii. p. 246. 
Hypsiglena texana, Stejneger, U. S. Dep. Agric. N. Amer. Faun. no. 7. pt. 2, p. 205. 
Hab. Nortn America, California, Texas (Laylor).—Mexico, Chihuahua and Guaymas 
(Cope), Presidio and Ventanas in Durango (forrer), Colima (Xantus), Guana- 
Juato (Duges), Jalisco (coll. Salv. & Godm.), Mezquital del Oro (Buller), Zacatecas 
(Cameron); Nicaracua (Mus. Brit.), Island of Laguna (Mus. Liverp.). 
Specimens of this species vary in the coloration of the neck, the two principal types 
of variation having been described as L. torquata and H. ochrorhynchus. We have, how- 
ever, another specimen from Jalisco, without distinct white collar, which shows only 
19 (not 21) series of scales, only 7 (not 8) upper labials, and which lacks the lower 
small preocular. Specimens from Zacatecas and Mezquital have also 19 (20) scales 
and 7 upper labials, but the collar is distinct; the lower preocular may be present or 
absent in the same specimen. Although these specimens differ somewhat in the shape 
of their head, I think that a larger series will prove their specific identity. 
2. Hypsiglena discolor. (Tab. XLIX. fig. A.) 
Leptodeira discolor, Giinth. P. Z. S. 1860, p. 317. 
Hypsiglena discolor, Cope, Bull. U.S. Nat. Mus. no. 82, p. 78. 
Hab. Mexico, Oaxaca (Sallé). 
The head is rather broad and depressed, the snout rounded ; the eye is of moderate 
size, its vertical diameter being about one-third the width between the eyes; the trunk 
is rounded and, like the tail, somewhat slender. The rostral shield reaches just to 
the upper surface of the snout; the frontals are nearly square ; the anterior pair are 
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