VIPERIDZ. 463 
of chin-shields, anterior longer than broad and in contact with four 
labials. Scales in 15 rows, vertebrals alittle enlarged. Anal entire; ~ 
subcaudals 51. Above wood-brown, with irregular narrow dark 
cross-bars interrupted on the spine; upper labials dark-edged ; lower 
parts with squarish light-edged black spots. 
Hong Kong (?). 
2. Pseudopareas atypicus. 
Leptognathus atypicus, Cope, Proc. Ac. Philad. 1874, p. 65. 
Rostral subtriangular; frontal and parietals broad and short; a 
subquadrate loreal; no preocular; two postoculars; temporals 
2+3; six upper labials, third and fourth entering the eye; first 
lower labial in contact with its fellow behind the symphysial ; four 
pairs of chin-shields, all except the first broader than long. Scales 
in 15 rows, equal. Colour pale, with black transverse spots, which 
are wide anteriorly and become gradually narrower posteriorly, 
where their lateral ends are broken off and alternate with the dorsal 
portion; a few small blotches on the ends of the ventrals, 
Total length 243 millim. ; tail 47. 
Andes of Peru. 
Fam. 9. VIPERIDA. 
Holochalina, part., J. Miiller, Zeitschr. f. Physiol. iv. p. 270, 1831. 
Viperidee, Bonaparte, Mem. Acc. Torin. (2) li. p. 393, 1840. 
Thanatophides, Duméril § Bibron, Erp. Gén. vi. p. 70, 1844. 
Viperina, part., Gray, Cat. Snakes, p. 3, 1849. 
Ee anspty plies, Duméril, Mém. Ac. Se. xxiii. p. 523, 1853 ; Duméril 
& Bobron, Erp. Gén. vii. p. 1859, 1854. 
Eurystomata icles part., Stannius, Zoot. Amph. p. 5, 1856. 
Viperide, Cope, Proc. Ac. Philad. 1859, p. 333. 
Viperiformes, Giinther, Rept. Brit. Ind. p. 383, 1864. 
Solenoglypha, Cope, Proc. Ac. Philad. 1864, p. 231. 
Viperide, Boulenger, Faun. Ind., Rept. p. 417, 1890. 
Facial bones movable; prefrontal not in contact with nasal; 
ectopterygoid (transpalatine) present, extending to mandible ; supra- 
temporal present, attached scale-like to the skull and suspending 
quadrate ; maxillary much abbreviated, erectile perpendicularly to 
ectopterygoid, supporting a pair of large poison-fangs without 
external groove. Mandible without coronoid bone. Hypapophyses 
developed throughout the vertebral column. 
Poisonous.—All except Atractaspis are ovoviviparous. 
This family includes terrestrial, semiaquatic, arboreal, and 
burrowing types. In the Crotalines, the passage from terrestrial 
to arboreal species is so gradual as to preclude their being referred 
to distinct genera. 
Europe, Asia, Africa (absent from Madagascar), America. 
