t 

 MAY, 1921. AMERICAN MARSUPIAL, C^ENOLESTES OSGOOD. 71 



that of Australian than American forms. It agrees quite closely with 

 Poulton's description of the tongue of Dasyurus and that in turn is 

 said to be of the same type as Halmaturus. 



Oesophagus. The oesophagus from the larynx to the stomach is 30 

 mm. long. It has membranous attachment to the vertebrae and lies 

 just dorsad of the aorta until it passes through the diaphragm and al- 

 most immediately joins the stomach in the middle of the lesser curva- 

 ture. Its lining has four to six longitudinal plications which continue 

 into the lumen of the stomach and hang free there. This condition of 

 the lining of the oesophagus evidently has general similarity to that 

 reported for most other marsupials except Didelphis. The transverse 

 folds of the lower oesophagus, which are characteristic of Didelphis* are 

 not represented in C&nolestes, but they are absent also in Marmosa and 

 Peramys. 1 The lower oesophagus of Marmosa is smooth, however, and 

 markedly different from that of C&nolestes. 



Stomach. The stomach (PI. VII, Figs. 4 and 5) of a male specimen 

 in somewhat distended condition measured 24 mm. in longitudinal 

 diameter and 16.5 mm. in transverse diameter. It is regular in form, 

 roughly elliptical, with the cardiac expansion only slightly exceeding 

 the pyloric. In gross examination, the interior shows three marked 

 divisions which may be called oesophageal, cardiac and pyloric, without 

 regard to their histological structure. The first or oesophageal division 

 is the smallest and consists of thin plications or lamellae surrounding 

 the orifice of the oesophagus and extending along the lesser curvature to 

 a point nearly midway between the oesophagus and the pylorus. The 

 cardiac division consists of a strongly differentiated glandular area, 

 forming a compound gastric gland comparable, at least in certain 

 respects, to the gastric glands of Phascolarctos, Phascolomys, and Manis. 

 It is developed principally on the sides of the stomach, being separate 

 on the two sides toward the pylorus but uniting around the cardiac side 

 of the oesophagus. In an undistended stomach, it is plainly evident 

 from the exterior through the rather thin outer muscular walls. From 

 within it appears as a thick, elevated, and well circumscribed area of 

 glandular tissue inclosing 40-60 slitlike openings (PI. VII, Fig. 5). 

 Especially toward the cardiac end of the stomach, these openings have 

 a distinctly linear arrangement and seem to be the result of an amalga- 

 mation of the usual rugae of the stomach. In an undistended specimen 

 there is one prominent fold or ruga which extends three-fourths of 

 the way to the pylorus and runs about midway between the compound 

 gland and the greater curvature. The pyloric division of the stomach 



1 This is a rather important distinction between Didelphis and Marmosa which, 

 so far as I am aware, has not been noted previously. 



