12 
Transactions of the Society. 
Tlie operculum of this species has the proximal edge straight with 
a movable “ appendage ” in the middle, ’which fits into a small notch, 
and is but slightly attached to the upper part of the operculum. The 
opercula of S. Cecilii Aud. and S. circinata MacG. are similar, and 
I have alluded elsewhere to this structure, and figured the operculum 
of S. circinata MacG. In all these species the ovicells are smooth. 
The curious webbed mandibles have the base symmetrical and not 
working in a socket, so that there does not seem to be any reason for 
considering the appendages vibracular. The mandibles are larger 
than those of any species with which I am acquainted. Mr. Busk 
speaks of S. vulgaris having vibracula, but according to my interpre- 
tation they are avicularia. 
Pasythea eburnea (Smitt), plate III. fig. 22. 
Gemellipora eburnea Smitt, Floridan Bryozoa, p. 35, pi. vii. figs. 
152-156, and pi. ix. figs. 177, 178. Pasythea eburnea Busk, Zool. 
Chalk Exp., pt. xxx. p. 5, pi. xxxiv. fig. 1. 
The operculum is complete, and is similar to that of P. tulipera 
Ell. and Sol., but I have not had the opportunity of making a prepa- 
ration of the last species. 
As the genera Pasythea and Liriozoa were created about the same 
time, it has seemed advisable to follow Busk, and to take the genus of 
Lamouroux. 
Pasythea is placed with Hippothoa and Eucratea under Eucra- 
.teadae by Busk, whereas Hippothoa and Gemellipora are put under 
the sub-family Schizoporellinae by MacGillivray ; and I should agree in 
placing this under Schizoporellinae, for the operculum is very similar 
to that of S. venusta and of some other forms now considered to belong 
•to Schizoporella. Found up to 450 fathoms by the ‘ Challenger.’ 
Loc. Florida (Sm.) ; Gulf of Gascogne (specimen sent to me by 
the late Dr. Jullien) ; 4 Challenger’ Stations 23,24 (West Indies), 
122 (off Brazil), and off Barra Grande, Brazil ; Madeira. 
Cellepora sardonica Waters. 
Cellepora sardonica Waters, Ann. Mag. N. Hist., ser. 5, vol. iii. 
p. 196, pi. xiv. figs. 2, 5, 5a, 6 ; Journ. Micr. Soc. ser. 2, vol. v. 
pp. 776 and 778, pi. xiv. fig. 39. 
In my paper ‘ On the use of the Avicularian Mandible in the 
•determination of the Chilostomatous Bryozoa,’ I have shown that the 
columella occurs in the round form of avicularia, but not in the tri- 
angular one, and that probably Busk examined only the latter when 
he stated that the columella was wanting. The ovicells have a circular 
line marking off an area. The young stage of a large number ot 
Celleporse is very similar, growing at first adnate and regularly, so 
that it is only in the older parts that there is any heaping up of the 
* Quart. Journ. Geol. Soc., vol. xliii. p. 64, pi. viii. fig- 41. 
