RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 4I 



It is to be noticed that the chitinous cuticle upon the upper su rfaces 

 of the folds bi\ is of considérable thiclaiess wtiere it encounters the under 

 surfaces of the pièce c, fig. 42, cl. 



In this détail it ressembles a similar disposition found between the 

 pièces of the same side in the Edriophthalmia called » plaques broyeuses«. 

 The under surfaces of the pièce c, however, are covered with a cuticle that 

 is remarkably délicate. 



The pyloric cavity differs considerably from our type. 



Although ail the pièces are found i",, 6',, S^s, SJ in their relative posi- 

 tions, the latéral plates 5, and the médian pièce S-^ are without hairs and 

 spines,; a few spines being found only upon the terminal point of the pièce 

 5j, FIG. 41, 42. 



There are no latéral grooves in the pièce 5-. 



At the posterior part of the chamber, the cuticle upon the latéral 

 plates becomes considerabl}^ thicker but only upon a very small surface 

 where the latéral plates are in contact with the médian pièce Sy 



The'inferior prolongations of the latéral plates PJ^ carry the typical 

 spines upon their borders, cf. fig. 16, 19, and what is very remarkable, 

 extend into the intestine for a considérable distance in the form of blades 

 becoming gradually finer till they terminate in sharp points. They carry 

 the spines upon their borders along their entire distance. 



In Nyctiphanes, therefore, the process of tearing and cutting the food, 

 or at least of mixing the food stuffs perhaps with the digestive ferments, 

 seems to be continued in the intestine itself. This may correspond with a 

 différence in the nature of the food of this more pelagic form. 



The posterior part of the pyloric chamber in which the digestive 

 glands open is very large, and contains a small médian pièce similar to 

 what is found in Gammanis, fig. 41, x. 



Miss CussANs has described this formation in Gammarus as a pair of 

 setigerous plates of cuticle at the origin of the digestive glands. 



In our species this pièce is unpaired. 



A pair of dorsal diverticula are found, their summits pointed towards 

 the stomach. 



They are glandular and excrète small round globules of a fat-like 

 nature which fall into the pyloric cavity behind the pièce iV Our prépara- 

 tions show that almost ail the pyloric chamber is filled with alimentary 

 matter very finely divided, especially at the anterior end beneath the plate c. 



