RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 35 



consequently no insertion of the arms bi\ in the hinder part of the ridge c, 

 FIG. 26, cf. FIG. 3. 



This ridge is rounded off at its posterior end and does not tenninate 

 in a pointed extremity. 



The séparation between the two chambers of the stomach, is therefore 

 much less marked in this species. 



The superior médian pièce is of the same forin as in our type. Whilst 

 the cardiac chamber is only slightly developed, the pyloric chamber, on 

 the other hand, is very voluminous in this species and attains a mucli 

 greater development than in ail the other Schizopoda, cf. fig. 26 and 3. 



The médian pièce 5, is depressed in the cavity, fig. 26, 28. 



The folds S^s, SJ do not meet in the médian line; there is no over- 

 lapping of the lower folds SJ, fig. 28, 29. 



This disposition in Macropsis ressembles that of the corresponding 

 pièces in the Edriophtalmia. 



The borders of the upper folds S,5 are fringed with short spines; the 

 lower with long hairs which, however, do not meet in the médian line, 



FIG. 28. 



The concave surfaces between the folds are covered with fine hairs. 



We saw that the superior border of the unpaired pièce 5; in our type 

 carried a bouquet ofstifif spines, fig. 15, whilst the inclined surfaces above 

 the latéral grooves were covered with fine hairs; in Aîacropsis, on the 

 other hand, there are no spines on the pièce S,, but ail the surface above 

 the grooves bears longer hairs than those found in Macroinysis flexuosa 

 and are at some distance apart, fig. 28, 29. 



The médian pièce 5^ possesses two pairs of latéral grooves with the 

 comb-like formations of the same nature as we saw in our type. 



An important structural différence is seen in the paired latéral plates 5,. 



There are no ribs fringed with spines running in curved lines along 

 théir internai surfaces; instead, we find in Macropsis two pairs of grooves, 

 with the comb-like spine formations, fig. 28, cf. fig. 15. 



The grooves, however, are much smaller than those of the pièce 5,. 



The concave surfaces above the grooves, as far as the folds 5^/ are 

 covered with hairs of the same kind and length as those found on the upper 

 surface of the pièce 5, and on the concave surfaces between the superior 

 folds, FIG. 28, 29. 



The lower surfaces of the plates S^ below the grooves are covered with 



