a General History of the Marine Polyzoa. 135 
In this beautiful species the oral sinus is almost circular 
and is connected by a narrow gap with the true orifice. It 
suggests very forcibly the special pore of the Microporellide. 
As bearing on the morphological relations of this portion of 
structure, an observation by Mr. Ridley is interesting. He 
has noticed a Myriozoidan stage in the development of a 
Porinidan cell, in which the pore had not yet become iso- 
lated, but was connected by a gap with the orifice *. 
CORRIGENDUM. 
Epicaulidium pulchrum, mihi. 
I have to plead guilty to a strange oversight respecting 
this beautiful form. When I gave it the above name 
(‘ Annals’ for Feb. 1881) it had quite escaped my recollec- 
tion that it was long ago described and accurately figured in 
Ellis’s posthumous work, edited by Solander, under the name 
of Cellaria tulipifera. A chance reference to the plates of 
this work (which I had not consulted for a long time) at once 
revealed to me my mistake, and has enabled me to make this 
early confession and correction of it. . 
Lamouroux reproduced in his ‘ Exposition’ Ellis’s figure ; 
but he ranged the species amongst the Sertularians, and re- 
ferred it to his genus Pasythea. Both De Blainville and 
Lamarck gave it generic rank, the one as Zuliparia (“Tuli- 
paire”), the other as Liriozoa; but Lamarck has changed 
(without any sufficient warrant, as it seems) Solander’s 
specific name. . 
EXPLANATION OF THE PLATES. 
Prats I, 
Fig. 1. Membranipora vitrea, n. sp. 
Fig. 2. Membranipora pyrula, n. sp. 
Fig. 3. Schizoporella tunuda, n. sp. 
Fig. 4. Monoporella > nodulifera, n. sp. 
Fig. 5. Mucronella porosa,n. sp. 5a. Ocecium. 
Fig. 6. Porella marsupyum, MacGillivray. 
Fig. 7. Cribrilina tubulifera, n. sp. 
fig. 8. Cribrilina speciosa, nu. sp. (This figure and fig. 5 are drawn to the 
same scale, and are much less highly magnified than the rest.) 
* “Polyzoa, Coelenterata, and Sponges of Franz-Joseph Land,” Ann. 
& Mag. Nat. Hist. for June 1881, p. 448. 
Tt This genus stands as Haploporella in the text; but Mr. Waters tells 
me that this name has been applied to a genus of fossil Foraminifera. 
