OCR Text |
Show 822 MR. G. S. WEST ON THE BUCCAL GLANDS AND [Nov. 19, the poison-gland. Anteriorly, however, it is greatly developed, and immediately below the nostril is of considerable bulk, sending off an upward prolongation anterior to that opening. The poison-gland is elliptical in form, is posterior to and somewhat remote from the eye, and sends off anteriorly a horizontal duct (PL X L V I . fig. 2). The Harderian gland (PL X L V I . fig. 19) is indistinctly divided into two lobes ; the anterior one is the larger and forms a socket for the eye, the posterior one is entirely buried in the muscles and is not visible externally. The eyes in this family of Snakes are comparatively small, with small round pupils, and the orbit is filled up to a great extent by the Harderian gland. The inferior labial gland is elongated and lies along the mandible external to the teeth. The maxilla (PL X L V I . fig. 9) is short, reaching but a little way in front of the eye. At the anterior end it is transversely enlarged and bears two large grooved fangs placed almost side by side, one-the slightly posterior one-being external to the other. They are but slightly curved and are inserted so as to point almost directly backwards. After a considerable interspace there are 5 more small solid teeth placed close together, the last one being at the extreme posterior end of the maxilla. In transverse sections of the grooved teeth they are seen to possess at the extreme end an anterior cutting-edge (PL X L V I . fig. 22). This was present only in this genus amongst those examined, the tooth at the apex being compressed laterally or in a direction at right angles to that in the case of Platurus. There are 10 mandibular teeth of approximately equal size, the anterior three being slightly further apart than the other seven. Genus PLATURUS. Species examined:-P. fasciatus. The superior labial gland tapers behind as in Enhydris, but does not reach quite so far back. The poison-gland is narrower and more elongated than in the former genus, and has a posterior downwardly curved portion not present in any of the other genera examined (PL X L V I . fig. 4). The Harderian gland forms a socket for the eye here also, the optic nerve passing through the postero-internal lobe of the gland (PL X L V I . fig. 18). The inferior labial gland is shorter and more robust than in Enhydris. The maxilla is extremely short and comparable to that of an Elapine Snake (PL X L V I . figs. 11 and 12). It is of a very peculiar form, and the two grooved fangs are situated side by side on its ventro-anterior edge. These teeth are large, and at about half their length are bent somewhat suddenly; they are very sharp and of a somewhat peculiar form. W h e n viewed from below they are seen to suddenly taper to an acute point near to the apex, the margins of the tooth being up to this almost parallel. W h en |