10 F. A. SMITT 



Membranipora canariensis (Pl. II, figs. 69 — 71) 



that species first described by Busk ') as belonging to the genus Cupularia. 



The zooecia, when they retain their membranous covering (fig. 69), show their 

 true membraniporidan constitution. The vibracularia, also, which of course are nothing 

 else than modifications of the same colonial organs as the avicularia, have their close 

 correspondence on the preceding forms, answering to the avicularia of the Membr. uni- 

 cornis. Here they are turned obliqnely backwards, in radiating as well as in lateral 

 direction 2 ) of the colonial growth, so that their tip is directed proximally, and the 

 margin of their opening (area), at the articulation of the bristle (vibraculum), on the 

 one side is raised in "a prominent tooth" above the level of its other side. 



When deprived of their primary ectocyst (fig. 70), the zooecia exhibit the inner 

 lamina in their area of the same form as that of the preceding species, and particul- 

 arly of the Farcimia cereus. 



On the back (fig. 71) the rounded thinnesses in the calcification, which are ex- 

 cavations or sometimes perforations (in the dried state) in the wall of the zooecia, 

 probably correspond with the above-named marks on the back of the preceding species. 



The Membranipora canariensis, after Pourtales' collections, seems to be very 

 common at Florida, from 10 to 44 fathoms depth. Through the kindness of Mr. Busk, 

 who first described it from Madeira, I have been able to compare it with specimens 

 from the coast of Marocco. Thus it is very widely spreacl in the Avestern hemisphere, 

 and a closer comparison with the Cupularia stellata, Busk, probably, I think, will show 

 it to have a yet wider distribution. 



Thus, in the natural series of Membranipora lineato-unicomis, with all surety, in 

 the Floridan sea we find three different modes of growth, viz: Membraniporidan, Rete- 

 poridan and Cupularian (auctt.). To these, I think, the Cellarian (Farcimia cereus) must be 

 added, although that form, through its peculiar calcification between the arese, has 

 gone far away, as it seems, in the deviation from the common origin. 



At the side of this series, as I formerly 3 ) have shown, the Lepralia nitida, auctt., 

 for the sake of its morphological relations is to be placed, although it offers the great- 

 est systematical interest in being one of the connecting links between the flustrine and 

 escharine types. And, indeed, its zooecial as well as colonial structure, particularly if 

 combined with that of Lepralia sceletos, Busk 4 ), must be regarded as Membraniporidan, 

 Yet, as it now can be demonstrated to represent the creeping state in a series, capable 

 of a still higher development, that series, suitably, ought to have its own generical 

 denomination, and I propose to name it M embraniporella. To that genus, then, should 

 be referred a very pretty species. 



!) Quart. Journ. Micr. Se, vol. VII, pag. 66, Pl. XXIII, figs. 6—9; Grag Polyzoa, pag. 87, PL XIII, fig. 2. 

 2 ) Compare Ofvers. Vet. Akad. Förh. 1867, pp. 391 and 405 etc., on the variations of the direction of these 



avicularia. 

 :I ) Krit. Fört. Skand. H. Bryoz., Öfvers. Vet. Akad. Förh. 1867, pågs. 366 and 401. 

 4 ) Quart. Journ. Micr. Se, vol. VI, pag. 262, Zooph., pl. XX, fig. 3. 



