72 FIELD MUSEUM or NATURAL HISTORY ZOOLOGY, VOL. XIV. 



is relatively smooth and undiff erentiated and is continuous with the area 

 along the greater curvature to the fundus. 



The- differentiation of areas of the stomach in Caznolesies is of course 

 a specialization and as such is referred to in discussion elsewhere, but 

 in view of the wide range of the character of the stomach in marsupials, 

 it is difficult to draw any direct inference of relationship. In fact, the 

 stomach of C&nolestes is unique and serves to strengthen the general 

 conclusion that the animal stands by itself quite as independently as 

 any of the highly specialized Australian forms. 



Intestines. The intestines lie in the abdominal cavity with the main 

 mass of the small intestines, or Meckel's tract, in ventral position. The 

 duodenal loop is well differentiated. On leaving the stomach (from 

 which it is separated by the pyloric sphincter, showing externally as a 

 distinct band 2 mm. in width), it passes slightly dorsad, then caudad and 

 turning sharply on itself runs cephalad a short distance ventrad of and 

 almost in contact with the colon, and thence it passes ventrad to the 

 center of the mass of Meckel's tract. Throughout this course it appears 

 to have slightly thicker walls than the distal part of the small intestine 

 and in an alcoholic specimen is lighter colored. The diameter of the 

 collapsed duodenum just beyond the stomach is nearly 9 mm. The 

 duodenum is weakly attached to the dorsal mesentery near the end of 

 its loop and very close to the colon. The folds of the intestines are 

 simple and on a continuous mesentery but cannot be straightened in 

 a preserved specimen without cutting. They seem to be in the condition 

 figured as stage II by Beddard (1908, p. 592, Fig. 121). 



The large intestine is relatively very short and straight and has no 

 indication of loops. It is scarcely more than 30 mm. in length as com- 

 pared to 340 mm. for the small intestine from the pylorus to the caecum. 

 The hindgut is imperfectly divisible into colic and rectal parts. The 

 colon has the usual longitudinal folds on its inner surface but at its 

 termination, that is at the beginning of the rectal part for a distance of 

 about 4 mm., both the large primary folds and the interspaces are crossed 

 by numerous delicate transverse ridges which in relaxed condition appear 

 as undulating transverse lamellae. Externally the rectum is covered 

 with longitudinal muscle fibers, somewhat more numerous dorsally 

 than ventrally. 



The caecum is very small, scarcely more than a vermiform appendix 

 (PI. VII, Fig. 3). In one specimen it is only 4.5 mm. in length; in another 

 it is 5.5. It opens into the intestine by a simple aperture and its inner 

 surface does not differ from that of the ileum. Immediately distad of its 

 opening the colon begins with a muscular, plicate inner surface in con- 

 trast to the villous surface of the ileum. 



