202 
THE VOYAGE OF H.M.S. CHALLENGER. 
such as the shape of the orifice and operculum, the presence of the small rostral semicircu- 
lar avicularium, which is sometimes terminal, sometimes seated below the summit, which 
ma} r be prolonged into an acuminate point beyond it, — but more particularly by the 
peculiar conformation of the numerous and large interspersed avicularia. At first I was 
disposed to divide the form into three species, Cellepora eatonensis, Cellepora magel- 
lensis, and Cellepora rostrata, but I am now quite satisfied that they are all specifically 
identical. 
(22) Cellepora ovalis, n. sp. (PI. XXVIII. fig. 5, and PI. XXXV. fig. 6). 
Character . — Zoarium ramose, branches cylindrical, tapering. Zooecia distinct, very 
prominent in the younger parts. Orifice orbicular, with a notch on one side. Pre-oral 
process strong, hollow, pointed, varying very much in height, and being much more 
prominent and pointed on the younger branches, than on the the main stem ; it supports 
an avicularium with a wide triangular mandible, the beak simple. Ooecia subrecumbent, 
with two or three raised pores in front. Interspersed avicularia few, of an oval form. 
Habitat. — Station 75, lat. 38° 37' N., long. 28° 30' W., 450 fathoms, sand (parasitic 
on a bundle of radical fibres of a Sertularian). 
The labial notch in this case resembles that which occurs in most of the Eetepores ; 
it is not median but placed to one side, and appears to have a tendency to become con- 
verted into a sub-oral pore. 
§§ /3. pisiform. 
(23) Cellepora bicornis, n. sp. (PI. XXX. figs. 1 and 12, and PL XXXVI. figs. 13, 15). 
Character. — Zoarium, globose. Zooecia ventricose below, becoming tubular above. 
Orifice circular, notched (fig. 12a); peristome much raised, tubular (fig. 126) and 
furnished in the perfect, sterile zooecia with two cylindrical pre-oral processes, having on 
their summits minute avicularia, with acute, triangular mandible ; besides these processes 
the peristome supports two to four spines, which in the perfect zooecia are replaced by a 
decumbent globular ooecium (fig. 12c), having a rounded fissure in front ; the surface other- 
wise of the ooecium is smooth and polished. A very few interspersed avicularia (fig. 12 d) 
with an excessively delicate membranous mandible of a broadly lanceolate form. 
Habitat. — Prince Edward Island, 80 to 150 fathoms. Marion Island, 50 to 75 
fathoms. Station 150, lat. 52° 4' S., long. 71° 22' E., 150 fathoms, rock. Station 314, 
lat. 51° 36' S., long. 65° 40' W., 70 fathoms, sand and gravel. Station 313, lat. 52° 20' S., 
long. 65 40' W., 55 fathoms (parasitic on Myriozoum truncatum and on Onchopora 
sinclairii ). 
