422 HOPKINS. [Vol. XI. 



form, — irregularly cylindrical or cubical-shaped; those next to 

 the ciliated cells of the mouth may perhaps be somewhat more 

 nearly cylindrical. 



The attached ends of most of the glandular cells are contin- 

 ued out into a sort of sheet-like prolongation which appears 

 to anchor the cells in place. Along the middle of the gland 

 the cells overlap each other in a manner very similar to the 

 scales of a pine cone, the apex of the cone corresponding to 

 the fundus of the gland. From numerous instances in which 

 the cells were traced directly into the mucosa it is believed 

 by the writer that in the Ganoids, at least, a basement mem- 

 brane does not exist. In Edinger's description of the stomach 

 glands in fishes he says that they possess no membrana pro- 

 pria or basement membrane, but that the epithelium borders 

 directl}^ upon the connective tissue of the mucosa. The cell 

 threads lie over each other like tile, so that they surround the 

 upper part of each gland with a kind of membrane which is com- 

 posed of innumerable fine threads, and sharply fixes the bounda- 

 ries of the gland. This appearance is obtained only in the cardiac 

 glands. In the pyloric region the glands are lined throughout 

 by cylindrical cells; in these glands no cilia were found. "The 

 differentiation of parietal cells, so far as is known, does not 

 occur in the class fishes, but is a phylogenetic occurrence which 

 appears much later in the vertebrate series." (Edinger.) 



SCAPHIRHYNCHOPS. 



Owing to lack of material, almost nothing can be said regard- 

 ing the form and appearance of the enteron in this genus. 

 The stomach is recurved upon itself in a manner similar to 

 that of the common sturgeon. At the pyloric end the muscu- 

 lar walls are thickened, but not to such a marked degree as in 

 the preceding. To all appearances the pyloric caeca are like 

 the common sturgeon's. The peritoneal coat is unpigmented. 

 In the oesophageal portion of the enteron are numerous large 

 fleshy papillae; these disappear some distance in front of the 

 pneumatic duct opening. In a specimen whose enteron, when 

 straightened, measured about 1 5 cm. from the air-duct to the 

 caeca, the papillae extended only to within about 3 cm. of the 



