22 



February 10, 1857. 



J. Gould, Esq., F.R.S., V.P., in the Chair. 



The following paper was read : — 



On the Anatomy of the Great Anteater (Myrmecophaga 

 jubata, Linn.). Part II. By Professor Owen, F.R.S., 

 F.Z.S., ETC.* 



In my former communication on the Anatomy of the Great Ant- 

 eater, the position of the stomach and its relations to adjoining vis- 

 cera were briefly pointed out. In the present paper I propose to de- 

 scribe the form and structure of this very remarkable organ in the 

 Myrmecophaga jubata. 



Moderately distended the stomach presents a subglobular form, of 

 about 8 inches diameter, with a smaller subglobular appendage, as 

 it seems, of about 3 inches diameter, intervening between the main 

 cavity and the intestine. 



The oesophagus terminates near the middle of the upper surface 

 of the main portion, of which about 4 inches extends to the left of 

 the cardiac orifice to form what Haller called the ' saccus csecus.' 

 The general configuration of the stomach, as seen from the anterior 

 surface, will be shown in the first Plate. 



On the middle of both the anterior and posterior surfaces of the 

 stomach is a sheet of tendon, of an irregular triangular form, 6 inches 

 in longest diameter, which is in the direction of the length of the 

 stomacb, and in which the tendon extends from the large to the 

 small division of the organ, and acquires upon the latter its greatest 

 thickness and whitest colour. 



Upon bisecting the stomach lengthwise, the part described as 

 the main cavity is seen to correspond with the cardiac division, and 

 the seeming appendage, with the pyloric division, of the stomach 

 in Rodcntia : but they are much more distinct in structure and 

 functions in the Myrmecophaga than in any other mammal with a 

 stomach similarly divided externally. The cardiac cavity has a vas- 

 cular secreting surface, the lining membrane being disposed in very 

 numerous small ruga; ; at the parts where the parietes have yielded 

 most to the distending force, these rugse are nearly effaced : other 

 larger and more permanent folds are nearly straight, are confined to 

 the vicinity of the communication with the pyloric cavity, and con- 

 verge towards the aperture. 



The cardiac orifice, in the inverted stomach, presents the form of 

 a narrow, slightly bent crescentic slit. It is situated about 3^ inches 

 from the similarly shaped aperture of communication between the 

 cardiac and the pyloric cavities : but the margin of this latter aper- 



* This paper will be reprinted in the Transactions, and there illustrated with 

 4 to plates. 



