306 DR. T. CANTOR ON PELAGIC SERPENTS. 
munis coledochus, which enters the duodenum a little behind the pancreatic duct; the 
latter has an entrance separated from that of the former’. 
The glands, generally speaking, are remarkably little developed in the Hydrophis 
schistosa, striata, nigrocincta, and gracilis, Schlegel. ‘The lachrymal is entirely hidden 
in the orbits ; the nasal is very minute, crescent-shaped, surrounding the posterior mar- 
gin of the nostrils ; the upper salivary appears like a short thread, bordering the venom- 
ous gland ; the inferior is larger, of a flat pyriform shape. The gland situated before 
the heart, and by some physiologists considered analogous to the thymus, by others to 
the thyroid gland* of Mammalia, is reduced to a minute oval body. 
Habits. 
Out of the seven species into which M. Schlegel has divided the Genus Hydrophis, 
the geographical distribution of which this author considers to be limited to the tropical 
seas between the 90th and the 230th degrees east longitude of Ferro, six inhabit the 
Bay of Bengal, viz. H. schistosa, striata, nigrocincta, gracilis, Pelamis, and pelamoides. 
Out of this number I have observed the H. schistosa and striata to be the most com- 
mon, and the H. gracilis comparatively rare in the northern part of the bay and the 
estuaries of the Ganges. 
Although fewer in species than the terrestrial serpents, the pelagic are much more nu- 
merous in individuals, and, unlike the former, are always met with in numbers together, 
which circumstance even serves as a sea-mark to mariners. On my approach to Bombay, 
I remember the sailors looking out for this phenomenon, until shoals of these animals 
(H. pelamidoides, Schlegel, Shiddil, Russell, II. No. xiii.) made their appearance, as signs 
of approaching land. Another remarkable dissimilarity between the terrestrial and pe- 
lagic serpents is, that all the latter are venomous, whereas by far the greater number of 
the former are innocuous. 
M. Schlegel has expressed the opinion’, that the pelagic serpents are of more peace- 
’ [ have observed a similar distribution in an Indian species of Homalopsis, closely allied to the H. aer, 
Schlegel. 
2 The discovery of this gland has shared the fate of many other organs, the functions of which, for want of 
inductive reasoning on the part of the discoverers, have been guessed, but never proved. The acmé of this kind 
of discoveries is however afforded by an anatomist, who, on finding a vascular organ in the nasal cavity of some 
Mammalia, gravely asserted this to be the seat of the sixth sense. The like assertions, unsupported by any- 
thing like proof, prove at the most, a remarkable want of inductive powers in the observer, while they also tend 
to show that a knife in expert hands may easily make new discoveries, the merit of which is solely due to the 
philosopher who tests and proves the truth—which is beyond the keenest knife. 
’ « Cependant, il existe des serpens tant vénimeux qu’ inoffensifs, qui ne font presque jamais usage de leurs 
armes pour se défendre contre leur aggresseur : tels sont parmi les premiers, les Hydrophis,” &c.—Essai sur la 
Physionomie des Serpens, Partie Générale, p. 94. 
“Tl parait que les Hydrophis ont des mceurs plus douces, que la plupart des serpens yénimeux,” &c.—Partie 
Déscriptive, p. 493. 
