General History of the Marine Polyzoa. 123 



doubt utilized as a brood-chamber. In other members of the 

 genus the ooeciura is external ; in the cells on which it occurs 

 (in 8. Rozieri, Audouin) the zocecial orifice is much larger 

 than in those Avhich are destitute of it, but does not equal in 

 size that of S. magnilahris. Above it an ample bilobate 

 structure is developed, forming, as it were, a dome over the 

 internal chamber, with the usual arched opening in front, 

 which is closed by the large operculum. In the ordinary 

 Cheilostomatous forms the inner chamber has no existence, and 

 the ooecium is a mere hood-like receptacle which overarches 

 the orifice, on the upper margin of which, or immediately 

 behind it, it takes its origin. In a previous paper (' Annals,' 

 August 1881) I have described a modification of the ooecium, 

 which consists of an extension of the cell itself, roofed in by a 

 number of marginal spines ; and there are many other forms 

 which have still to be investigated. The morphological his- 

 tory of the ooecium has yet to be Avritten. 



The following species belong to the genus Steganoporella : — 

 8. Rozieri^ Audouin : Rio de Janeiro {Darioin) ] Mazatlan 

 {Dr. P. F. Carjjeriter) \ California {T. //.) ; Zanzibar (IF. 

 Gates) ; India {3Iiss Jelly) ; Australia {MacGillivray) ; form 

 falcifera^ ibid. {Miss Jelly). 8. 8mittiij Hincks {=Memb. 

 Andeyavensis, Busk) : Cornwall {Peach) ; North Australia 

 {Goldstein) ; Coralline Crag (-S^ear/eA' Wood). 8. Neozelanica, 

 iJusk : New Zealand {Dr. Lyall). 8. magnilahris, Busk { = 8. 

 elegans, Smitt): Abrolhos Islet, Atlantic (Daricin); Algoa Bay 

 {Bowerhank) ; Singapore (7'. //.) ; Bass's Straits {Cawne 

 Warren). 8. {Membranipora) perforata^ MacGillivray (pro- 

 bably a form oi 8. Rozieri), Victoria ; and perhaps Vincularia 

 Novie Hollandice, Haswell : Queensland. 



The species which I have described (' Annals,' Nov. 1880) 

 under the names of 8. Jervoisii and 8. elongata are referable 

 to the genus Micropora, as is also the Vincularia steganojyo- 

 roides of Goldstein. 



Family Monoporellidse. 



MONOPOEELLA, Ilincks. 



Monoporella albicans, n. sp. (PI. V. figs. 5, 5 a, 5 h.) 



Zoaecia ovate, very irregularly arranged, convex, surface 

 minutely granular, shining ; orifice arched above, lower margin 

 straight or very slightly curved outward, peristome not 

 raised; just below the oriticc a rostrum, with an avicularium 

 on one side, mandible short, rounded ; large avicularia dis- 

 tributed amongst the cells, elongate, the beak at the extremity 



9* 



