140 MARINE BIOLOGY OF THE SUDANESE RED SEA. 
are surely synonyms, of which 7 hairopora is the more satisfactorily diagnosed. 
Harmer, in his “‘ Revision of the Genus Steganoporella,” refers to the structure 
of Siphonoporella *. 
Loc. Victoria, Ceylon; Engineer Island, Khor Dongola, collected by 
Crossland. 
MeEMBRANIPORA LIMOSA, sp. nov. (Plate 12. figs. 1-5.) 
The zoarium attains to at least 80 mm. in length, and is formed of long, 
quadrilateral, dichotomising branches ; except for a short distance below the 
bifureation there are four zocecia in a series; but where the branches divide 
the zoarium is hexagonal. It bifurcates at a rather narrow angle, about 40°, 
and in this respect corresponds with several species of Farciminaria. The 
zoarium is about 0°6 mm. in width, the horny walls are thick but contain a 
moderate layer of calcareous matter. At the bifurcation the walls of the 
zocecia become phenomenally thick, and in these thick-walled zocecia no 
polypides were found. 
The zocecia are about 0°85 mm. in length, and the opesia about 0°6 mm. 
At the base of the opesial opening there is a small denticle, which often 
spreads out at the end. ‘The denticle may easily be overlooked until 
preparations are made. No ovicells or avicularia have been found. ‘There 
are numerous distal pores round the edge. 
There are 15 tentacles, and sections do not reveal any intertentacular 
organ; but I have found it impossible to cut satisfactory sections of this 
species. 
The zoarial growth is the same as that of Farciminaria, but the zocecia are 
so Membraniporidan and similar to the M/. Savarti group, that it is placed 
under Membranipora. The ovicells of Farciminaria differ considerably from 
those of Membranipora. 
The zocecia are much shorter than in any ‘ Challenger’ Farciminaria, which 
vary from 1°26 mm. to 2°78 mm., while &. Alice, Jull. & Calv., is 2°36 to 
255 mm. Busk calls Fareeminaria an “ emphatically abyssal” genus, 
although F’. brasiliensis occurs from 32-400 fathoms. The M. limosa seems 
to be abundant, and is found from 10 fathoms in mud, from which cause the 
name is chosen. MacGillivray ¢ says that the three Australian species of 
Farciminaria were dredged from a depth of 10-15 fathoms. 
Busk, in his ‘ Challenger’ Report, gives the genus Farciminaria as “ sub- 
membranaceous or corneous,” but all have a thin calcareous skeleton ; even 
F, uncinata has thin caleareous walls, and the inner wall of the ovicell is 
entirely calcareous. F'. aculeata and other species have a Membraniporidan 
* Quart. Journ. Micros. Sci. vol. xliii. p. 232 &e. 
t Prod. Zool. Vict. dec. xvi. p. 219. 
