TOTO. | N. ANNANDALE: Phylactolematous Polyzoa. 51 
Plumatella bombayensis, Annandale. 
P. bombayensis, Annandale, Rec. Ind. Mus., vol. ii, p. 169, figs. 1, 2. 
Zoarium. ‘The whole colony is recumbent but branches freely 
-and at short intervals in a vertical plane, so that the zocecia become 
‘crowded together and the branches sometimes overlap one another. 
The zoarium often covers a considerable area, but growth seems 
‘to be mainly in two directions. 
‘Zoecia. The walls of the zocecia are thick, stiff and densely 
pigmented; the external surface, although not very smooth, is 
always clean; a flat membrane, which is apparently an extension of 
the ectocyst, frequently extends between different zocecia and 
‘branches. The two most noteworthy characters of the zocecia 
are (I) their truncated appearance when the polypide is retracted, 
and (2) the conspicuous, although often irregular external annulation 
of their walls. The tip of each zocecium, owing to the fact that the 
tentacular sheath is soft and sharply separated from the stiffened 
wall of the tube, terminates abruptly and is not rounded off 
gradually as is the case in most species of the genus ; sometimes 
it expands into a trumpet-like mouth. The annulation of the 
-external surface is due to numerous thickened areas of the ectocyst 
that take the form of slender rings surrounding the zocecium ; they 
are most conspicuous on its distal half. On the dorsal surface of 
the base of each zocecium there is a conspicuous furrowed keel, 
which, however, does not extend to the distal end; the latter is 
-oval in cross-section. The zocecia are short and broad ; their base 
is always recumbent, and, when the zoarium is attached to a stone, 
often seems to be actually embedded in the stone ; the distal part 
turns upwards and is. free, so that the aperture is terminal ; the 
zocecia of the older parts of the zoarium exhibit the specific 
-characters much more clearly than those at the growing points. 
Polypide. ‘The lophophore bears 20 to 30 tentacles, which are 
long and slender; the velum at their base extends up each tentacle 
in the form of a sharply pointed projection, but these projections do 
not extend for more than one-fifth of the length of the tentacles. 
Both the velum and the tentacular sheath bear numerous minute tu- 
bercles on the external surface. The base of the stomach is rounded, 
and the whole of the alimentary canal has a stout appearance. 
Statoblasts. Both fixed and free statoblasts are produced, 
but not in very large numbers. The latter are broadly oval and are 
‘surrounded by a stout chitinous ring, which often possesses irregular 
membranous projections ; the surface is smooth. The free stato- 
‘blasts are small and moderately elongate, the maximum breadth 
as a rule measuring about 2 of the length ; the ring of air-cells is 
not very much broader at the ends than at the sides ; the dorsal 
‘surface of the central capsule is profusely tuberculate. The outline 
‘of the whole structure is somewhat irregular. 
This species is perhaps no more than a variety or a local race 
of the African P. tanganytke and is closely related to P. philippinen- 
sis; from the former it differs mainly in its darker and more stronglv 
