44 On the Dentition o/" Hydrophis viperina. 



pupil, separated from the labials by suboculars ; nostrils 

 superior, pierced in the upper part of the nasal ; a pair of 

 internasals ; a single prteirontal ; rostral small, not promi- 

 nent ; loreal, pra3- and postocular present. Scales finely 

 striated and feebly keeled (in seventeen rows). Tail mode- 

 rate, tapering to a fine point. Anal and subcaudals divided. 

 An annectant form between the Calamaringe and the 

 Homalopsinse. 



Calamohydrus Andersonii. 



Prasfrontal more than twice as broad as long, in contact 

 with the posterior border of the nasals and wedged in between 

 the tear-shaped internasals, which form a suture anteriorly ; 

 frontal pentagonal, a little longer than broad, and a little 

 shorter than the suture between the parietals ; eye surrounded 

 by a small supraocular, which is more than twice as long as 

 broad, a pra30cular, two suboculars, and a' postocular ; loreal 

 elongate, more than twice as long as deep, in contact with the 

 third and fourth labials -, temporals 1 +2 ; eight upper labials, 

 fifth below the eye ; nine lower labials, five anterior in con- 

 tact with the chin-shields, first in contact with its fellow 

 behind the mental ; two pairs of chin-shields, anterior large, 

 posterior small and separated by three scales. Scales in 

 seventeen rows, without apical grooves ; the keel very feeble, 

 absent on the hinder third of the scale. Ventrals 161 ; sub- 

 caudals 58. Blackish above, each scale edged with whitish ; 

 lower parts whitish ; chin and lower labials brown. 



Total length 240 millim. ; tail 45. 



The same colle'ction contained an adult specimen of a 

 rare sea-snake, Hydrophis vij^ervna, Schmidt [Disteira prce- 

 scutata, D. & B.), which reveals a new ijpe of dentition. 

 The maxillary oi i\\e, Hydrophides is armed, as is well known, 

 with a pair of grooved fangs, followed after an interval by a 

 series of much smaller solid teeth. In H. viperina we have 

 instead a series of four equidistant, subequal, grooved fangs. 

 The Calamaria-X^k.^ Ogmodon vitianus, Peters, was the only 

 snake known to possess a series of grooved fangs ; but the 

 number and proportions of these fangs are very different from 

 what is shown by Hydrophis viperina. 



Schmidt, the original describer of this species, notices that 

 the teeth are small and show no trace of a groove, and regards 



