162 MARINE BIOLOGY OF THE SUDANESE RED SEA. 
? Schismopora cucullata, Maplestone, “ Lord Howe Island,” Proc. Roy. Soe. Vict. n. s 
vol. xvii. (1905) p. 389, pl. 29. fies. 7, 8. 
Cellepora albicans, Waters, Quart. Journ. Geol. Soc. vol. xxxviii. (1882) p. 512. 
There is no true opercular sinus, but there are two wide denticles in the 
oral aperture, which sometimes nearly meet and are frequently unsymmetrical. 
The operculum is entire below, and in the same way “ Schizoporella”’ 
subsinuata, Hincks, has a notch in the peristome without the operculum 
corresponding, and has therefore to be removed from Schizoporella. These 
teeth in the specimens from Ras el Millan are very pronounced (see Pl. 18. 
fig. 20), but in those from the Bay of Agig they are small and only form 
a square notch. There are two or four tapering oral spines and a minute 
semicircular avicularium on a short rostrum below the aperture, the surface 
of the zocecium is granular, and there is a row of pores round the border. 
There are large, erect, vicarious avicularia, and the mandible has the columella 
characteristic of the group. The ovicell is a wide open cap, also a generic 
character. The oral aperture is not so large as in most of the genus, and 
the operculum has the two ridges turning inwards as in C, tuberculata, Busk, 
C. jacksoniensis, Busk, C. polymorpha, var. samboangensis, Busk, C. tridenti- 
culata, Busk, C. atlantica, MS. Busk. 
There are about 17 tentacles. 
It has been overlooked by some authors that Hincks, in 1893, said that he 
found on re-examination that the Monoporella albicans, Hincks, and Schizo- 
porella aperta, Hincks, were synonyms. 
Loc. Singapore or Philippines (Hincks), Andamans (Th.), Kalingapatam 
(Th.), Manaar (Th.). Ras Osowamembe, Zanzibar Channel (504). Red Sea; 
Bay of Agig Suraya (21), Khor Dongola (19), Khor Shinab, 10-12 fath. (3), 
Shukuk, 9 fath. (11), Suez (18), collected by Crossland; Ras el Millan, 
Sinai coast, and Gimsah Bay, collected by Hartmeyer. Cuba, d’Orbigny 
coll., Mus. d’Hist nat. Paris, 13782. 
Fossil. Bairnsdale, Victoria ( Waters). 
HonoporeLia Descostinsu (Audouin). (Plate 16. figs. 1, 2, 3.) 
Cellepora Descostilsii, Aud. “ Expéd. de l’Egypte,” Zool. p. 238, pl. 7. fig. 11; d’Orb. 
Paléont. Frang. vol. v. p. 401. 
Zoarium formed of several layers. Zocecia coarsely granular, with a few 
large pores visible in the younger zocecia. The lower lip is much raised into 
a narrow ridge, as shown by Savigny. 
The large vicarious avicularia stand up erect in many cases, as figured by 
Savigny, and the border is serrate. The lower edge of the operculum is 
straight, and the muscular attachments are high up close to the side. The 
denticle or condyle at each side of the oral aperture can sometimes be 
distinguished. There is, as a rule, no oral avicularium in the lip, though in 
looking over considerable pieces I have seen one or two. The mandible of 
RR a a hos i aS a ae a 
