A. W. WATERS—REPORT ON THE BRYOZOA. 159 
LaGEnrpora Costazit (Audouin), var. SPATHULATA, MacGillivray. 
Cellepora Costaztt, var. spathulata, MacG. Prod. Zool. of Victoria, dec. xv. p. 185, pl. 148. 
fie. 6. 
Zoarium pisiform. Zocecium erect, ovate ; peristome not much extended, 
with a triangular avicularium at one side. Opereulum nearly round, with the 
muscular dots a distance from the borders. Only one vicarious avicularium 
has been found. Ovicell \rather higher than is usual in Lagenipora, area 
perforated round the border. 
There are 13 tentacles. 
I believe that this is the C. Costazdi var. for which MacGillivray suggested 
the name spathulata*, though there is no mucro, neither does MacGillivray 
figure any. Also in some other species he speaks of a mucro where none 
is figured. 
Neviani has made a genus Costazia f, of which the L. Costazi is the type ; 
but his Costazia celleporina, Nev. t, belongs to the holostomatous group, 
showing that the genus was not based upon satisfactory characters. 
Lagenipora seems to be a very natural group, the opercula throughout 
being similar, and in most cases about the same size ; also the ovicell at the 
side of the peristome has a flat area and pores round the border. 
Loc. Dredged at Suez, among lamellibranchs covering the dock walls 
(no. 18). 
HOLOPORELLA, gen. noy. 
The lower lip of the aperture is more or less straight, the operculum has 
the muscles attached near the border, sometimes with a ridge § running 
inwards; the ovicell is a widely open cap. There are usually oral and vicarious 
avicularia, and the mandible of one of the two usually has a small projection 
from the base which Busk called the columella. Most species have an 
exceedingly minute avicularium at each side of the zocecium, at the distal 
end, but in some they are no longer functional, only vestigial (Pl. 17. figs. 22. 
23) ; also the oral glands are long and tubular, sometimes irregularly folded. 
Many species are very dark, nearly black. 
In 1879 I showed that the operculum of Cellepora sardonica, Waters, had 
a straight proximal edge; and Busk, in his ‘Challenger’ Report, makes a 
division (§ 1) of forms of Cellepora with a straight border to the oral aperture, 
* Zool. of Victoria, dec. xv. p. 185, pl. 148. figs. 5, 6 (1887). 
+ “ Bri. Neog. di alcune Loc. Ital.” pt. i1., Boll. Soc. Romano per gli Studi Zool. vol. iv. 
p. 239 (15), 1898. 
¢ “Coral e Bri. Neog. di Sardegna,” Boll. Soc. Geol. Ital. vol. xv. p. (24), 1896. 
§ The opercula of many Bryozoa have a ridge for the attachment of the tentacuiar 
sheath. 
