302 PROCEEDINGS OF THE ACADEMY OF [1887. 



specimens described and figured by Seeliger. The middle glandular 

 cusliiou consists of eleven long pear-shaped cells, arranged with their 

 large ends towards without, giving a section of the cushion a kid- 

 ney-shape. The contents of these cells have none of the coarsely 

 granular look of those of the "inner" glandular cushion, but present 

 a faint longitudinal striation; they bear very clear round nuclei in 

 their basal portions, in the centre of which are prominent round nu- 

 cleoli. Below the "middle" glandular cushion is the so-called "out- 

 er intermediary band," (fig. 8, oib.) but this is again different from 

 any described by Fol. Instead of consisting of simple pavement cells 

 it is here made up of three layers of spindle-shaped cells with long 

 rod-like nuclei ; the inner layer of cells bearing fine short cilia. 

 The "outer intermediary band" as figured by Seeliger, differs from 

 those of Fol and myself in being composed of non-ciliated columnar 

 cells. The "outer glandular cushion" (ogc. fig. 8) is composed of 

 eleven cells very like those of the "middle" glandular cushion, and 

 arranged after the same manner, pear-sha}:)ed with large ends to- 

 wards without. They present however several nucleoli in each nu- 

 cleus instead of but one. The two halves of this cushion forming 

 together the floor of the endostyle present their largest curves in an 

 exactly opposite manner to that figured by Fol, but similar to that 

 of Seeliger. The basal jiortions of the largest cells of the two halves 

 lie together in place of being turned away froin one another. In 

 none of my specimens have I been able to find the exceedingly long 

 cilia, nor the two small oval cells described by Fol as bearing them, 

 and as lying between the right and left halves of the "outer gland- 

 ular cushion." 



The Alimentary canal begins with a trumpet-shaped pharynx (ph 

 fig. 9,) the everted edges of which pass over into the entodermal 

 lining of the inner mantel. Its celb are rather long, cylindrical and 

 hyaline, with small clear nuclei in the basal portions ; they bear 

 coarse lancet-shaped cilia. The character of the cells remain the 

 same throughout the oesophagus, (oe fig. 9) which is considerably 

 contracted in diameter; but upon reaching that portion of the canal 

 which corresponds to the stomach of DoUolum, although there is 

 no special dilatation of the canal, they lose their cilia and assume 

 a somewhat more cuboidal character appearing at times to be piled 

 loosely upon one another in several layers. Just here where the 

 ciliated epithelium of the oesophagus changes into that of the stom- 

 ach, the alimentary canal is joined by two coecal appendages, one 



