A. W. WATERS—REPORT ON THE BRYOZOA. 163 
the vicarious avicularium has the lucida low down, and there is no columella, 
which occurs in the mandibles of most species of //oloporella. The ovicell is 
a wide open cap (fig. 1), as usual in the genus. The small piece from Ras 
el Millan has two oral spines, and the oral glands are tubular and more or 
less contorted. 
Loc. “ Polyzoa from lamellibranch shells, 30.11.04. Dredged near the 
quay-wall, Suez” (18), collected by Crossland ; Ras el Millan, Red Sea, 
collected by Hartmeyer. 
HoLopoRELLA PIGMENTARIA, sp.nov. (PI. 15. figs. 16-19; Pl. 16. figs. 9-16; 
Pl. 17. figs. 22-23.) 
The zoarium, formed by several layers of zocecia, is irregularly mamillate; 
the surface is very dark or black, though sometimes the raised mamilla 
is white. 
The zocecia near the growing edge are horizontal, with pores round the 
border, and the rest of the coarsely granular or nodulated surface is im- 
perforate. A rostrum projecting from the lower lip has a triangular 
avicularium. There are vicarious avicularia, serrate at the edge, having 
long spatulate mandibles without a columella. Besides the ordinary pores 
round the border of the zocecium, there is a large one belonging to the two 
neighbouring zoccia (Pl. 15. fig. 16). In specimens from Ras el Millan 
there are also very minute avicularia by the side of the zocecium (PI. 1%. 
figs. 22, av., 23); however, in various species of Holoporella these minute 
avicularia are only seen on a few of the zoccia, while in others they are 
general. 
There are 17 tentacles, and the glands are tubular, though not so long as 
in some other species. 
This species is much like Cellepora mamullata, Busk, and it is separated 
from it with diffidence, but the operculum spreads out at the base, whereas in 
C. mamillata the operculum, prepared from the type, has the sides nearly 
straight. 
The fact of the zoarium being mamillated is not of primary importance, 
as there are many species in which the zoccia are in the same way arranged 
in regular heaps. 
This is a dark species, and a further study of the pigment in C. vermiformus, 
Waters, C. albirostris, Smitt, &c., would be of considerable value. 
The colour is caused by a quantity of light brown, round cells with minute 
nucleus near the border. ‘These are found inside the zocecium near the 
walls and sometimes a few close up to the tentacular sheath ; then they fill 
the pore-tubes, and on the outer surface of the zocecium spread from one 
pore-tube to another, gradually forming a thick layer over a good part of the 
surface of the zocecium (PI. 16. fig. 16). On the front of the zocecium the 
