58 REPTILES. 
** Labial shields occupying only the front half of the lips : eyes over 
the fifth or sixth shield: hinder part of lips covered with small 
scales : ventral scales generally free, two-rowed, forming a keeled 
ridge, or sometimes united in pairs into a flattish six-sided 
shield. 
9. Hyprus. 
Scales elongate, lanceolate; of the neck longer and more acute, 
keeled: eyes small; pupil round. 
Hydrus, Gray, Zool. Misc. 60, 1842. Hydrus sp., Shaw, Zool. - 
iii. 558. Pelamis sp., Merrem. 
1. The Sea Snake. Hydrus major, Shaw, Zool. iii. t. 124. 
Gray, Zool. Misc.60. Pelamis Shawii, Merrem, Tent.139? Hy- 
drus Stokesii, Gray, in Stokes’s Australia, App. 4, t. 3. 
White in spirits; dorsal and ventral edge with alternate broad 
and narrow black cross-bands ; sides with a series of small roundish 
spots, becoming nearly uniform whitish when adult; labial shield 
reaching to the eye. 
Var. 1. Hinder labial shield small, triangular, with the scales 
above them larger and transverse. 
a. In spirits. Half grown. Anterior ocular moderate; hinder ocu- 
lar shields 3, small; ventral shields almost all separate. India. 
Old collection. Described by Dr. Shaw. 
H. major, Shaw, Zool. 
b. Inspirits. Half grown. Anterior ocular 1, posterior 2; the 
front ventral shield united into cordate, smooth plates; rest 
lanceolate, separate. Port Essington. Presented by the Earl 
of Derby. 
c. In spirits. Very young. Scales short, blunt, polished, very ob- 
scurely keeled: white; back with alternate broad and narrow 
black cross-bands ; sides with a series of roundish black spots, 
and with an alternate series of small black spots and short 
cross-bands. Port Essington. Presented by the Earl of 
Derby. 
Var. 2. Stokesit. The hinder labial shields moderately large, 
subtriangular, rather high, as large as the series of scales above 
them. 
d, In spirits; bleached. Adult. Hinder ocular 2. Australian 
Ocean. Presented by Captain Stokes, R.N. 
Hydrus Stokesii, Gray, l. c. t. 
