'43 



The ova have a large round nucleus with nucleolus set in a 

 massof yolk spherules, the whole sometimes reaching 1-5 mm. 

 in length by nearly i mm. in breadth. The nucleus is usually 

 situated in the upper part of the cell, and in a fortunate series 

 of sections I found near the base of two ova small canals ex- 

 tending through the endoderm. These open from the exo- 

 coelic side, and reach down to the surface of the ova, one of 

 which seems to have partially flowed into its canal. 

 The diameter of the canals is in each case about that of 

 a human, red blood-corpuscle, and the sections, which 

 are not quite so thick, appear in both cases to have 

 been cut almost longitudinally through the centre of each 

 channel. The bounding endoderm shows longitudinal striae 

 in the walls, but the existence of canals is quite clear under a 

 high power. Although I have examined many other ova I 

 have not found these oviducts elsewhere, and I suspect that 

 they are merely temporary structures for the escape of the 

 ova. They have not been previously described, so far as I 

 am aware, in the Madreporaria, and are almost certainly what 

 the Hertwigs described as the " Fadenappart " of the ova in 

 the Actimaria * 



The single polyp of F. pavonnuuii, that I examined, is in 

 rather a different condition, so far as digestion is concerned^ 

 to any of those of the above species that I have worked over. 

 It, however, only differs in its minute anatomy from F. 

 rubriLui in that mucous gland cells are more conspicuous 

 and numerous both in the ectoderm, and more especially 

 in the endoderm. 



8. ON THE POST-LARVAL DEVELOPMENT OF 

 F. RUBRUM. (PL III, figs. 10-16.) 



Dried Coralla. — The corallites of dredgings 4 and 5 in 

 particular have various stages of the development of the 

 species growing upon them. In the earliest stage found 

 there is a distinct round basal plate with 6 septa radiating 

 from the centre, but not meeting one another. There is no 

 trace of epitheca. As yet it is uncertain whether the young 

 corallite belongs to Flahelhtiii or to a fungid coral, which I 

 have also found growing on some of the specimens. The 

 earliest undoubted stage is that of a corallite, nearly 2 mm. 

 in diameter, with a distinct epithecal rim, -z--^ mm. high,, 

 and 6 primary and 6 secondary septa (fig. 10). Another, 

 almost similar, has the epitheca -5 mm. high showing the 



* Die Actlmcn [1879].— PJate vii., Fig. 13, very closely resembles the appearance 

 If ound, but the membrane of the ovum in my section is distinct and the nucleus at 

 the opposite end of the cell (Fig. 2). 



