418 G. HERBERT FOWLER. 



tween which the canals lie are not homologous with true costse, 

 since the latter (which are generally regarded as the ends of 

 the septa, projecting radially outwards beyond the theca) are 

 also represented round the lip of Amphihelia. They may per- 

 haps bear some relation to the echinulations of coenenchy- 

 matous forms ; but here, as in most questions of Madreporarian 

 morphology, a close investigation of a large number of allied 

 forms is necessary for a true explanation of structure. 



A figure and description of the corallum may be found in 

 Milne-Edwards and Haime in ' Ann. Sci. Nat/ (3) xiii, p. 86, 

 pi. iv, fig. 3. 



Stephanophyllia formostssima (figs. 4, 5, 6). 



Professor H. N. Moseley has kindly handed to me for further 

 investigation part of a decalcified specimen of this polyp, of 

 which he has already published a partial account in his mono- 

 graph of the Deep-Sea Madreporaria obtained by the " Chal- 

 lenger" ("Chall." Rep. Zool. ii, p. 203, pi. xvi). Owing to the 

 fragmentary nature of the material, I am unable to give a 

 detailed account of the general anatomy, but it is still possible 

 to make out some points of interest. 



As is the case in Fungia, and in the embryo Astroides de- 

 scribed by von Koch and Lacaze-Duthiers, the corallum is 

 plano-convex, resting free and unattached upon its plane 

 surface. The latter constitutes the theca, and from it the 

 septa rise perpendicularly upwards. The theca consists of 

 a large number of concentric and radial trabecular, and from 

 the radial trabecular rise alternately a mesentery and a septum 

 (fig. 4). The septa are thus both ectoccelic and entoccelic, 

 and, like the concentric trabecular from which they spring, lie 

 free in the ccelenteron, not touching the body Avail. On the 

 other hand, those radial trabeculse to which the mesenteries 

 are attached, lie directly on the basal body-wall, and are united 

 with it just as are the ridges and spikes in Amphihelia and 

 coenenchymatous forms. 



Stephanophyllia therefore appears to stand in much the same 

 relation to the family Eupsammidse, with which it is generally 



