OCR Text |
Show 682 MR. F. G. PARSONS ON THE [Nov. 20, cristata and H. javanica, it will be noticed that the general resemblance is very great. The chief points of difference are:- 1. That the scales are more deeply serrated in Hystrix. 2. That the fungiform papillae are more numerous. 3. That the foliate papillae have more ridges and grooves. In the specimen of H. javanica examined there were sixteen parallel grooves, while in that of H. cristata there were twenty. I do not know whether the number of ridges and grooves in the foliate papilla? is constant in different individuals of the same species. The tongue of Erethizon clorsatum described by Mivart1 differs a good deal from that of Atherura. There is no median groove except at the hinder margin, while the serrated scales so remarkable in Atherura and Hystrix are not noticeable. Buccal cavity. O n each side of the mouth there is a small cheek-pouch lined with hair, and opening between the incisor and premolar teeth. The pharynx is a continuation of the oesophageal tube up to the posterior nares. There is a small round opening into the mouth in its anterior wall, just above the laryngeal aperture. There is no uvula. The oesophagus is narrow above and is remarkable for the thickness of its mucous membrane. The stomach is simple and resembles that of M a n in its shape ; it differs from Hystrix cristata and javanica in the absence of the sacculus, and from that of Erethizon in not being bent on itself and in its less elongated form. The pylorus has a very thick muscular ring Avith a calibre only large enough to admit a small quill. Immediately to the outer side of this is the opening of the large bile-duct. The pancreas is a solid tongue-like gland situated behind the stomach ; as the viscera were somewhat decomposed before they came under observation, I failed entirely to find the pancreatic duct or its place of opening. The spleen resembles that of Hystrix in being a tongue-like gland, without any notches, situated close to the great cul-de-sac of the stomach. Its total length is 3^ inches. In Erethizon this organ is oval. The duodenum forms a large open loop, its calibre at first is very great, but it narrows rapidly. The great omentum is about 1 inch long, it reaches a httle beyond the umbilicus, but not as far as the bladder. The small intestine is 15 ft. 4 in. long, including the duodenum. The ccecum is very much shorter than in Erethizon, being only 1\ inches instead of 28. The ileo-caecal valve is an oval opening \ inch long, the lips of the valve are slightly patulous. There is no sacculus rotundus and no constriction as in Erethizon at the place where the caecum joins the colon. The mucous membrane 1 P.Z.S. 1882, p. 271, |