60 Zoological Society : — 



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 Rodentia : 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 rugae ; at the parts where the parietes have yielded 

 most to the distending force, these rugae 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- 

 ture is indented as it were by the ends of the converging folds of the 

 lining membrane, about ten in number, which are continued into the 

 pyloric cavity. The length of the cardiac slit is 1 inch ; that of the 

 intercommunicating aperture is 1 inch 3 lines. 



The pyloric division of the Anteater's stomach is remarkable for 

 the thickness of its muscular tunic and the density of its epithelial 

 lining, which convert it into a veritable gizzard. 



The muscular coat varies from one inch to half an inch in thick- 

 ness ; at the middle of the cavity it is separated from the lining 

 membrane by an unusual accumulation of the elastic submucous cel- 

 lular tissue, which is most accumulated in the upper wall of the 

 cavity. A very small proportion, only, of food can enter at one 

 time into this cavity, to be subjected to the triturating force of its 

 parietes, operating with the aid of swallowed particles of sand in the 

 comminution of the unmasticated or imperfectly masticated termites. 



The area of the pyloric cavity, as exposed by a vertical longitu- 

 dinal section, appears a mere linear, slightly sinuous tract, with a 

 dilatation near the pylorus, due to a kind of valvular protuberance 

 of the upper wall projecting towards that aperture. But, when the 

 pyloric cavity is bisected transversely, its area then presents a cres- 

 centic figure, owing to the protuberance formed by the thicker mus- 

 cular tunic and the more abundant submucous elastic tissue in the 

 upper parietes. The lower longitudinal plicse, which commenced on 

 the cardiac side of the intercommunicating aperture, give a longitu- 

 dinally ridged character to the inner surface of the cavity. 



This character is changed, near the pylorus, for a reticular rugo- 

 sity : the pylorus, when viewed from the duodenal side, presents a 

 crescentic form, with the horns of the crescent directed upwards. 

 The lining membrane of the duodenum soon becomes smooth. 



Mr. Gould communicated the following letter, lately received by 

 him from M. Elsey, Esq., the Surgeon and NaturaHst attached to 

 the Expedition under the command of A. C. Gregory, Esq., now 

 engaged in exploring the north-western and northern portions of 



