578 
G. HERBERT FOWLER. 
Mouth-disc = Mundscheibe, Peristome. 
Body wall = Leibeswaud. 
Stomodaeum (oesophagus) = Scblund-, oder Magen-robr. 
Coelenteron = Darmhoble, Leibesbohle, Estomac. 
Mesenteries (sarcosepta) = Scheidewande, Parietes, Replis 
mesenteroides. 
Mesenterial filament (craspedon) = Mesenterialfaden, Cordon 
pelotonne. 
Septa (sclerosepta) = Sternleisten, Cloisons, Lames. 
Theca = Mauerblatt, Muraille. 
A “ pair ” of mesenteries is constituted by two mesenteries 
whose longitudinal muscle-fibres are ranged on their adjacent 
faces, (except in the case of the two “ directive pairs,” each of 
which is placed at one end of the longer axis of the mouth 
oval, and in which the arrangement of the muscles is reversed). 
For the chambers (Radial-taschen, Loges,) into which the 
coelenteron is periaxially divided by the mesenteries, I am 
compelled to coin new names; to those chambers which lie 
between a “pair” of mesenteries the term entocoele is applied 
(fig. 1 , b) ; to those chambers of which one lies between every 
two pairs of mesenteries the term exocoele (fig. 1, a). The 
septa lying in these two classes of chambers are similarly 
called exosepta and entosepta 
The classification adopted will be found at the end of the 
paper, together with the bibliography. 
Recent Researches into the Morphology of the Group. 
In 1873 Lacaze Duthiers (1), studying the development of 
Astroides calycularis on the coast of Algiers, found that it 
agreed in every important point with the development of 
Actinia, his observations on which (2) were corroborated and 
corrected by the Brothers Hertwig (3). With regard to the 
developing skeleton, he recorded two facts of importance : 
firstly, as appears in his pi. xiv, fig. 27, that it was formed 
outside the polyp; and secondly, that the theca arose 
independently of the septa. Owing to various practical 
difficulties his investigation was incomplete. 
The chief worker in this field has been Georg von Koch, 
