Zoological Society. 503 



PROCEEDINGS OF LEARNED SOCIETIES. 



ZOOLOGICAL SOCIETY. 



Oct. 26, 1841.— William Yarrell, Esq., Vice-President, in the Chair. 



The following communication, entitled, " Description of the Sto- 

 mach of the Colobus Ursinus, Ogilby," by R. Owen, Esq., was read. 



" The body of the Ursine Colobus, which there can be little doubt is 

 the Full-bottom Monkey of Pennant {Colobus poly comos, lUig.), lately 

 exhibited in the Society's menagerie, having been transmitted to me 

 for examination by Mr. Waterhouse, with a view more particularly to 

 the determination of the form of the stomach, I have much pleasure 

 in communicating to the Society the result of this examination. 



" It may render the interest in the dissection of this Monkey more 

 intelligible to some, if I premise, that the genus to which it belongs 

 is one of recent discovery or establishment, the affinities of which to 

 the Doucs (Semnopithecus), though strongly illustrated by the general 

 form of the Colobi, and more especially by their skull and dental 

 organs, required a knowledge of the anatomy of their digestive sy- 

 stem for its full appreciation. 



" The Colobi, peculiar among all known old world Simiadce by the 

 rudimental development of the thumbs of the fore-hands, were gene- 

 rically separated on that account by lUiger. Cuvier, at the period of 

 publishing the last edition of the ' R^gne Animal,' had not enjoyed 

 the opportunity of determining how far the distinctive character, seized 

 upon by the Berlin naturalist, was real and constant. Temminck, 

 however, had assured Cuvier that the Colobus of Illiger possessed the 

 skull and dentition of the Semnopitheci. Mr. Ogilby has mainly 

 contributed to establish the lUigerian genus and illustrate its extent 

 by the description of several species founded upon skins transmitted 

 to the Zoological Society ; and our excellent establishment has now 

 fulfilled another of its functions, by affording to the anatomist the 

 means of establishing the natural affinities and position of the genus 

 Colobus, as it has heretofore done in regard to the Semnopithecus. 



" The stomach of the Colobus Ursinus presents the same compli- 

 cated saccular structure as in the Semnopitheci : if it was somewhat 

 smaller in the present instance, in proportion to the body, this might 

 arise from the immaturity of the individual examined. The saccula- 

 tion is produced by the same modification of the muscular fibres of 

 the stomach, combined with a great extent of the digestive tunics. 

 A narrow band of longitudinal fibres traverses the lesser curvature 

 of the stomach, and a second band, commencing at the left or blind 

 extremity of the cavity, puckers it up in a succession of sub-globular 

 sacs along the greater end. I deem it unnecessary to pursue the 

 description more minutely in this case, as it would be merely the 

 repetition of that which has already been published in our Transac- 

 tions in reference to the Semnopithecus Entellus"* . The form and size 

 of the csecum, and the length and disposition of the intestinal canal 

 in the Colobus equally corresponded with those parts of the anatomy 

 of the closely allied genus Semnopithecus." 

 * Vol. i. p. 65. pi. 8. 



