REPOET OR THE POLYZOA. 
123 
raised and prominent in front. Ooecia rather large, globose, with a trifoliate stigma. 
Anterior adventitious avicnlaria very sparse, in the form of cylindrical, slightly curved, 
obliquely truncated columns, which spring from the front of a cell (fig. 5c), and have 
a blunt duck-bill shaped mandible. At the lower angle of many of the fenestrse retentive 
avicularia occur, in the form of a boat with a double prow (fig. 5e), each of the prows 
having a bifid beak, and each branch of the furcate, membranous mandible fits into one 
of the bifid beaks, the space between the branches of the fork being partially filled with a 
delicate membrane (fig. 5 cl). 
Dorsal surface shining, finely granular or submuricate, with distant indistinct 
vibices, and a few immersed avicularia of the same conformation as the fenestral, but of 
very much smaller size. 
Habitat. — Station 190, lat. 8° 56' S., long. 136° 5' E., 49 fathoms, green mud. 
This species, which has several characters in common with Retepora tubulata, is, how- 
ever, at once distinguished by its peculiar mode of attachment by means of solid columnar 
dorsal processes, which are doubtless homologous with the chitinous tubular processes, by 
which several escharan species of Membranipora and Dicichoris are attached. The 
anterior columnar avicularia also form a conspicuous feature, altogether wanting in 
Retepora tubulata. These may, perhaps, be regarded as homologous with the columnar 
dorsal processes. 
(18) Retepora philippinensis, n. sp. (PI. XXVII. fig. 5). 
Character. — Zoarium (in a single specimen) about 1 inch long, infundibuliform, with 
the sides pinched in. Fenestrae very small, circular, and very uniform in size. Celliferous 
surface external, dorsal (or non-celliferous) surface interior, smooth, dull. Zooecia 
urceolate, distinct. Orifice orbicular. Peristome thick, deficient or slightly tuberculated 
behind, slightly raised in front and on the sides ; sometimes subcanaliculate in front. 
Labial fissure, or rather sinus, rather wide and shallow. Ooecia conspicuous, acuminate 
in front, with a row of three or four punctures close to the border of the orifice (fig. 56). 
Avicularia 0 (?) 
Habitat. — Station 212, lat. 6° 54' N., long. 122° 18' E., 10 to 20 fathoms, sand. 
As the only specimen is a small dead and imperfect fragment, the general habit and size 
of the zoarium and the characters of the chitinous parts cannot be stated, but it probably 
consists of a congeries of infundibuliform or trumpet-shaped alveoli. One peculiarity 
consists in the circumstance that, contrary to the usual arrangement, the celliferous surface 
is on the outside of the folds ; and another peculiarity is the apparently complete absence 
of avicularia of any kind. 
