50 Charles GELDERD 



aware, no other author has pointed out the homologies in this group of the 

 Crustacea. 



Frey (') in his description of the stomach of Alacronijsis Jlexuosa, 

 mentions simply the latéral pièces of the cardiac chamber; the latéral teeth 

 escaped his observation, and he did not attempt to indicate the homologies. 



He considered the stomach oi Alacromysis to be less developed than 

 that of the Decapoda, but more complicated than that of the Isopoda and 

 Amphipoda; " médium inter utramque formam locum tenere videtur«. In 

 his memoir on the Podophthalmia, Mocquart (-) disagrees with Frey and 

 finds a great similarity between the Schizopoda and the -lower Decapoda». 

 Mocquart is the only author, as far as we are aware, who has tried to find 

 homologies between the stomach pièces of the Decapoda and the Schizopoda. 



He has studied many species of Podophthalmia and his memoir con- 

 tains numerous drawings of dissections. 



He has not, however, made any microscopical sections and consequently 

 his descriptions are wanting in détail. 



His drawings of the dissecied pièces are, moreover, very small and 

 difficult to understand. 



His treatment of the Schizopoda is most unsatisfactory, for he dévotes 

 his descriptions of this group to a single species of Mysidse which he had 

 not determined. 



We think it will be useful, however, to summarise his descriptions and 

 conclusions : «les pièces ordinaires de l'armature stomacale sont mécon- 

 r> naissables; il y a deux dents latérales dont la situation est normale. La 

 r. dent médiane fait défaut, mais il y a une sorte de préparation à sa forma- 

 " tion comme à celles des pièces pyloriques et propyloriques ; on n'observe 

 » dans la région pylorique aucune pièce squelettique distincte. " 



From this short description it will be seen that Mocquart failed to 

 observe some of the pièces in the stomach of the Mysidae. 



He concludes in the following terms : ^il est impossible de mécon- 

 n naitre les rapports qui existent entre le squelette gastrique des Mysis et 

 " celui des Décapodes inférieurs. La division cardiaque de l'estomac en 

 r^ particulier, par sa forme, par les dents latérales, les plaques cardiaques, 

 » les pièces cardiaques latérales inférieures et les rudiments de pièce pen- 

 « née, rappelle exactement ce qu'on observe chez beaucoup de Salicoques. « 



f) Frey : Loco citato. 



(*) Mocquart : Loco citato. 



