194 
Mr. A. W. Waters on the 
The oral aperture lias two small hinge-projections, which 
give the appearance of a distinct sinus, which is not shown in 
the operculum. 
The operculum (fig. 7) is nearly orbicular, with hinge-notches 
near the distal end. Width 0’24 millim., length 0108 millim., 
muscular dots O’OS millim. apart. 
I lab. West of Tortugas, 42 fathoms ; Naples, brought by 
coral-fishers from considerable depths (the fishermen said 
from 500 fathoms; but it is not likely to be nearly as much). 
64. Cellepora retusa , Manz. 
Cellepora retusa, Manz. Bri. di Castrocaro, p. 34, pi. v. fig. 59. 
? Cellepora coronvpus, Manz. Bry. Foss. Ital. cont. 4, p. 13, pi. in. 
figs. 18,19. 
Cellepora tubigera, Waters, Bry. from Bruccoli, Trans. Manch. Geol. 
Soc. vol. xiv. p. 475, figs. 20, 21. 
Decumbent tubular cells with usually two distinct avicu- 
larian processes at the side of the aperture. The surface is 
smooth in all specimens I have seen. Ovicell globular, per¬ 
forate ; aperture long and narrow. 
This I have incrusfing, in one layer, on Eschara cervicornis. 
It may be the form sometimes figured as tubigera , which, in 
my opinion, is only another stadium of C. coronopus. 
The operculum is long and narrow, with an acute proximal 
end, edges entire ; length 0T72 millim., width 0T28, muscu¬ 
lar impressions 0068 millim. apart. 
The Celleporce are such an intricate genus, and so much 
stress has been laid upon the mode of growth, that their deter¬ 
mination is a matter of great difficulty and the synonymy 
very uncertain. 
65. Cellepora retusa , var. caminata. (PI. XIII. fig. 1.) 
Zooecia tubular, elongate, narrowing towards the distal end ; 
peristome raised above the aperture, with two or three long 
tubular avicularia raised over the aperture ; occasional zooecial 
avicularia ; ovicell globular, flat on the upper surface, which is 
perforate. Operculum long and narrow. 
The sketch (fig. 1) is not a camera-lucida drawing, but is 
drawn to show the cells when perfect and when worn at the 
.ends. The walls are porcellaneous, thick, with fine tubes in a 
longitudinal direction ; these in the inside end with a fine 
perforation. A somewhat similar structure is shown in some 
of Savigny’s figures ; but in older specimens this becomes 
scarcely visible, and ultimately cannot be made out. 
Small adnate convex zoaria (about 5 millims. in diameter) 
of this species are common on seaweeds. 
