No. 2.] ENTERON OF AMERICAN GANOIDS. 425 



The mode of epithelium transition and the presence of folli- 

 cles, or crypts, in front of the pneumatic duct opening corre- 

 sponds to those forms already noted, except that the follicular 

 area is considerably shorter than in either of the preceding. 

 The epithelium of the cardiac portion of the stomach is ciliated 

 (Fig. 21). Owing to the shortness of the cilia and the pres- 

 ence of a thin layer of extraneous matter on the surface of the 

 epithelium, considerable difficulty was experienced in detecting 

 the cilia in this specimen. Among the ciliated epithelium cells 

 were a great many beaker cells; the peripheral end of these 

 takes scarcely any stain, and appears to be open, or without a 

 membrane over the free end. The nuclei of the cells are very 

 large, some oval and others circular in outline, and many of 

 them contained several darkly stained granules. The cells 

 lining the mouths of the glands are much shorter than those 

 on the free surface, but nevertheless they possess fully as large 

 nuclei as the latter; in other respects no differences between 

 the cells in the two situations were observed. In this genus the 

 mucous membrane presents certain features not found in any 

 of the others. The gastric glands are so convoluted that it is 

 almost impossible to get sections in which the whole length 

 of the gland appears; usually the glands are cut at various 

 angles to their long axis, so that perhaps two or three succes- 

 sive sections must be examined in order to study the gland 

 throughout its whole extent. The relative lengths of the mouth 

 and body of the gland are nearly equal (Fig. 18). The lumen 

 of the glands was specially large in the specimen examined, 

 and appeared to be of about the same size at all points except 

 the mouth, which, of course, was somewhat larger. In several 

 instances it was noted that the diameter of the lumen measured 

 at least one-quarter the whole width of the gland (Fig. 20). 

 Several glands open into a single mouth. The gastric cells 

 which line the body of the glands have, at their attached ends, 

 a very slight thread or sheet-like continuation for attaching 

 them to the mucosa. The tile-like overlapping of the cells is 

 very slight ; often the dividing line between two cells extends 

 directly across at right angles to the long axis of the gland. 

 The cells are finely granular and stain lightly, especially the 



