14 G. HERBERT FOWLER. 



chamber walls" is not justified by the examination of sections; 

 the two longer and more developed mesenteries with their 

 filaments, 3. 10, lie, as in Seriatopora, for their whole length 

 in the coelenteron. 



Apparently, any of the mesenteries may bear generative 

 organs, and it is worthy of remark that the polyps are 

 monoecious. The ovaries and testes, though surrounded by 

 a thin capsule of mesogloea and endoderm, as in typical forms, 

 do not lie, as is generally the case, in the plane of the mesente- 

 ries (cf. fig. 3), but project from their sides in a manner more 

 characteristic of certain Alcyonaria, so that in transverse 

 sections of the colony they frequently appear to lie free in the 

 coelenteron. Two stages in the development of the sperma- 

 tozoa are figured as well as the preservation of the material 

 would allow (figs. 14, 15). 



In both this and Seriatopora there was left, after decalcifica- 

 tion, a residue in the position occupied by the corallum, which, 

 though staining faintly both with hsematoxylin and with borax 

 carmine, showed no distinctly organic structure. 



In transverse sections of the polyps it is just possible to 

 detect, at the point of the insertion of the mesenteries in the 

 corallum, structures similar to those described by Sclater (11) 

 as calicoblasts. Their excessive minuteness in Pocillopora 

 rendered an accurate investigation impossible, but they cer- 

 tainly appeared to me to be rather connected with the attach- 

 ment of the mesentery to the corallum than with the secretion 

 of coral. 



Milne-Edwards and Haime, ' Hist. Nat. des Corall/ iiij, p. 

 301, pi. f4, figs. 1, 2. 



Agassiz, • Nat. Hist. United States/ iv, 295, pi. xv, 14. 



Klunzinger, l Korallthiere Roth, Meer./ ii, 6Q, pis. vii, viii. 



Note on the Skeleton of Flabellum. 

 In his latest addition to the literature of the subject (9), the 

 main part of which I do not propose at present to discuss, 

 Dr. von Koch treats, amongst others, of the skeleton of 

 Flabellum. 



