180 PROFESSOR OWEN ON THE ANATOMY OF THE GREAT ANTEATER. 



but the margin of this latter aperture is indented, as it were, by the ends of the con- 

 verging folds of the lining membrane, about ten in number (e, e), which are continued 

 into the pyloric cavity. The length of the cardiac slit (6) is 1 inch, that of the inter- 

 communicating aperture (/) is 1 inch 3 lines. 



The pyloric division of the Great 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 (PI. LII. fig. 2, h, h) varies from one inch to half an inch in 

 thickness ; at the middle of the cavity it is separated from the lining membrane by an 

 unusual accumulation of the elastic submucous cellular tissue (i), which is most abun- 

 dant in the upper wall of the cavity. A very small proportion only of food can enter 

 at one time into this cavity {k), to be subjected to the triturating force of its parietes, 

 operating, with the aid of swallowed particles of sand, in the comminution of the un- 

 masticated or imperfectly masticated Termites. 



The area of the pyloric cavity, as exposed by a vertical longitudinal section, as in 

 fig. 1, Plate LII., 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, as in fig. 2, 

 its area then presents a crescentic figure, owing to the protuberance formed by the 

 thicker muscular tunic and the more abundant submucous elastic tissue (i) in the upper 

 parietes. The lower longitudinal plicae {k), which commenced on the cardiac side of the 

 intercommunicating aperture, give a longitudinally ridged character to the inner surface 

 of the cavity. 



This character is changed near the pylorus, for a reticular rugosity : the pylorus, 

 when viewed from the duodenal side, as in Plate LIII. fig. 2, presents a crescentic 

 form, with the horns of the crescent directed upwards. The lining membrane of the 

 duodenum (to) soon became smooth. 



For the use of the accurate and beautiful drawings, made after my dissections by 

 Mr. H. V. Carter, formerly Anatomical Student in the Museum of the Royal College 

 of Surgeons, which illustrate the present portion of the anatomy of the MyrmecopheCga 

 jubata, I am indebted to the liberal permission of the President and Council of the 

 Royal College of Surgeons of England. 



