EUDOXIA. 57 



THE DIPHYOZOOIDS. 



Eschscholz, in defining his genera of Diphydan Siplionophora, lays great stress upon 

 the character of the digestive apparatus. Certain genera have a " tubulus suctorius unicus," 

 others have the " ductus nutritorius (cocnosarc) tubulis pluribus obsitus." 



As I have already had occasion to mention, Lesson seizing upon the distinction thus 

 indicated, divided his "■Bipliydce " into two very natural groups — the Polygastricm (tubulis 

 pluribus) and the Monogastricm (tubulo unico). 



In the first division he arranged the genera Biphyes, Calpe, and Abyla; in the second, 

 Cymba, Enncayonum, Ciiboides, Cucubalus, CucuUus, Eudoxia, Amphiroa, Erscea, and Aylaisma. 



Neither by Will, Busch, nor myself was the true nature of the "monogastric Diphydse" 

 suspected, but Leuckart's investigations cited above, appear to me to leave no doubt that 

 these apparently independent forms are nothing more than detached zooid forms, or 

 independent portions of the " polygastric Diphyda;." I have grouped them together, there- 

 fore, under the head of " Diphyozooids ;" and though it is necessary, so long as the genesis 

 of each Diphyozooid has not been worked out, to retain their distinct generic and specific 

 titles, and even to invent new ones for undescribed forms, yet these names can only be 

 regarded as provisional. 



Gems EUDOXIA {Eschscholz). 



Diphyozooids derived from Diphyes (?). 



The hydrophyllium is lamellar and evenly convex externally. The walls of the cavity 

 which contains the polypite are incomplete on one side. The phyllocyst is simple and 

 conical. 



Eudoxia Lessonii {Eschscholz). PI. Ill, fig. 6. 



Ersaea Quoyi, Eschscholz, 1829. 



— Gaimardi, Idem. 

 Diphyes cucullus, Quoy and Gaimard, 1833. \ 



Erscea pyraniidalis, ? Will, 1844. 

 Eudoxia Eschscholzii, ? Busch, 1851. 

 — campanula, Leuckart, 1853. 

 GaleolaricB pullus, Vogt, 1854. 



This Diphyozooid attains the length of four tenths of an inch. The hydrophylhum occupies 

 from less than a half, to two thirds of the whole dimensions. It is thick and irregularly 



8 



