RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 63 



FIG. 10. Drawing of a dissection of the grooves in one of the faces of the 

 pièce S} highly magnified. The posterior ends of the grooves unité in a concave 

 cavity, free from spines, through which the sécrétions from the digestive glands pass 

 into the grooves. The surface above the grooves is covered with very fine hairs. 



FIG. 11. Horizontal section passing through the upper portions of the cardiac 

 and pyloric chambers. The concave internai surfaces of the plates Sj are seen 

 covered with hairs. The terminal part of the pièces are armed with teeth. In 

 br^ the chitinous folds connect the pièces of the cardiac chamber with the folds 

 5iS which run above the upper portion of the pyloric cavity terminating close to 

 the dorsal diverticulum div. The first two pairs of dorsal tubes of the digestive 

 gland are seen in transverse section. 2/3 in, X 5. 



FIG^ 12. Horizontal section passing at a lower level than the preceding figure 

 through the upper portions of the cardiac and pyloric chambers. The lower folds 

 br^ connect the latéral pièces S^ with the lower folds S^i which run above the 

 pyloric chamber. Thèse folds become free as blade-like projections P,/, at the en- 

 trance to the intestine. Their terminal bordera carry a comb-like apparatus of long 

 spines. From the dorsal aspect thèse chitinous pièces are slightly convex at their 

 terminal end. 2/3 in, X 5. 



FIG. 13. Horizontal section at a still lower level through the two chambers 

 of the stomach. The longitudinal ridge which runs between the latéral plates of the 

 cardiac chamber is seen in transverse section c. The two chambers are entirely 

 separated from one another at this level. The dorsal aspect of the upper portions 

 of the paired latéral pièces S^ of the pyloric chamber with the chitinous surface 

 ribs is seen in 5,, r. The upper ridge of the médian pièce S3 has been included 

 in the section. 2/3 in, X 3. 



FIG. 14. Horizontal section through the lower portions of the two chambers. 

 The lower bordera of the cardiac pièces Sj are seen in bi. The pyloric cham- 

 ber contains the three pièces. The latéral plates Sj are convex and fit into the 

 concave latéral faces of the médian pièce S^. The section has passed through the- 

 entrance of the common canals of the digestive gland into the posterior portion of 

 the pyloric cavity. The latéral inferior pockets p. l. i. are also shovvn. 2/3 in, X 5. 



FIG. 15. Transverse section through the plane indicated by the same number 

 in FIG. 3. The folds S^s and S^i are withdrawn, thus allowing food to pass through 

 the lower folds into the pyloric cavity below. The surface ribs, bearing spines, are 

 seen in the latéral pièces 5;. The comb-like apparatus facing the grooves in the 

 latéral surfaces of S3 are seen in transverse section. The upper portion of the pièce 

 is covered with very fine hairs. The summitofSs is fringed with spines. D Zeiss, X I- 



FIG. 16. Section at an angle of 45" to the axe of the animal, to indicate 

 the relations between the posterior surface of the médian pièce 5^ and the terminal 

 under pièce of 5,, P^/;. The terminal blade-like plates P^k carry spines upon their 

 inner borders. 2/3 in, X 3. 



