OCR Text |
Show 120 MR. F. E. BEDDARD ON BRACHYURUS CALVUS. [Feb. 1, the colour gradually assumes a fulvous-brown tint, the brown being darker in the pectoral region, where the brown hairs are very numerous, only a few white hairs being interspersed among them. The brownish tinge is also conspicuous on the arms, legs, and tail, particularly on the tail, on the posterior aspect of the thighs, and at the wrist and ankle. The top of the head is a greyish colour, gradually passing into brown anteriorly and at the sides, as in B. rubicundus; the hairs on the throat also resemble that species in their dark brown colour, and in being mixed with numerous black hairs ; the general tint of the hair on the throat is a rich chestnut-brown, and is exactly similar to that of B. rubicundus. With regard to the osteology, I find that the number of vertebrae in m y specimen is C. 7, D. 13, L. 6, S. 4, Cd. 15, of which the last three are very minute and apparently ankylosed together. Forbes states in his paper that in B. melanocephalus there are 19 or 20 caudal vertebrae, on the authority of a specimen belonging to that species in the National Collection. The specimen in question (806 b) has certainly the 20 caudal vertebrae that Forbes has mentioned ; but it does not present any recognizable differences from Brachyurus calvus, and indeed is entered in the Catalogue as belonging to that species. It is not necessary to give much account of the visceral anatomy of this species, inasmuch as I have been unable to find any marked points of difference from B. rubicundus ; the alimentary viscera presented a very close correspondence in the two species, as will be evident from the following notes. The tonyue resembles in every particular that of B. rubicundus, and, curiously enough, even the arrangement of the circumvallate papillae corresponds in the two species. The correspondence is curious, because Mr. Forbes's description of the circumvallate papillae reads almost as if he were referring to an abnornal condition. The circumvallate papillae in the two species are disposed in the usual V-shape, but there is an additional papilla on the right side between the apical and basal papillae, thus destroying the symmetry of the arrangement. In a specimen of Macacus rhesus, to which I am able to refer at the moment of writing, there are also four circumvallate papillae ; two are situated side by side, and symmetrically at the apex of the V, while the two others occupy the usual position. Cacum-The csecum measured 10 inches along the greater curvature ; it is separated from the colon by a very marked constriction; it is not sacculated, and when fully distended with air was curved on itself into a little less than a circle ; it is furnished with a well-developed median frenum which carries blood-vessels. In examples of two species of Callithrix and in a Pithecia I have noted an identical structure in the csecum. The origin of this peritoneal fold is not exactly in the middle line at the low er extremity of the ileum, and the blood-vessel passes on to it over one side of the base of the ileum ; the blood-vessel in fact exactly corresponds to that which is borne by one of the lateral folds in Hapale. |