RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA f, I 



MocQUART insists on the fact that in each natural family, the stomach 

 apparatus is, in gênerai, built upon a spécial type proper to each family, 

 and in spite of numerous différences of détail found in the varions groups, 

 the modification of the gastric skeleton consists merely in a change of form 

 or of relationship between the pièces, brought about by their coalescence 

 or disappearance. 



In no case, according to Mocquart, are new pièces added to the 

 stomach; even in the case where the apparatus has been most changed, the 

 homologous pièces may be established with certitude. 



According to this author, then, in ail the Podophthalmia, the stomach 

 is built upon the same plan. 



The resuit of our research has led us to consider the following as 

 homologous pièces in the Schizopoda, the Edriophthalmia and the Deca- 

 poda : 



The latéral pièces in the cardiac chamber of the Schizopoda armed 

 with teeth, hooks or spines 5i represent the «crêtes dentées ou hispides" 

 of the Edriophthalmia and the latéral pièces armed with teeth of the 

 Decapoda. 



The latéral pièces of the pyloric chamber of the Schizopoda 5, are 

 homologous to the latéral pièces in the same chamber of the Edriophthal- 

 mia and Decapoda. 



The unpaired médian pièce Sj of the pyloric chamber of the Schizo- 

 poda is the same pièce as the unpaired médian pièce of the Edriophthalmia 

 and Decapoda. 



In the three groups, pièces may exist in some species that are not 

 found in others. 



For instance, the superior médian pièce p. s. m. which is found in the 

 Schizopoda and Decapoda, is wanting in the Edriophthalmia except in the 

 case of Idotea. 



The •'lames recouvrantes « and the •'lames annulaires ^^ described by 

 Professor Ide in the Edriophthalmia, are not found in the Schizopoda. 



The first are epithelial folds running horizontally above the two cham- 

 bers of the stomach in many Edriophthalmia : Oniscus, Armadillo, Asel- 

 lus and Idotea. 



They are not found in Anilocra and Gammanis. 



The "lames annulaires- are ring-like folds in the anterior portion of 

 the mid-gut; Gammanis, Idotea and Vibilia possess a single fold ; two are 

 found in Oniscus. 



