1903. ] FROM EAST AFRICA AND ZANZIBAR. 951 
rhinophore-pockets and the anal papilla project ; the edges are 
smooth. In the preserved specimen the rhinophores are grey. 
The branchiz ave arranged in a circuit interrupted only by the 
head and genital papilla. They vary in size, but though in places 
long and short branchi seem to alternate, this cannot be said to 
be the general rule. 
Over the mouth are two tentacles each about 1:5 millim. long, 
and 1 millim. broad at the base. They are not directed sideways 
but straight forward, and being set close together so that the 
division is not visible, they appear to form a sort of head. They 
are united at their bases. The mouth is larger than is usual in 
this order, and though it is suctorial is hardly poriform. Though 
the animal was dissected only three months after capture, the 
internal organs were already much dried and shrivelled, the spirit 
having apparently been unable to penetrate the hard integument. 
It was clear, however, that the buccal organs are of the type of 
Phyllidiopsis rather than Phyllidia. The buccal opening led into 
a sausage-shaped tube about 6 millim. long and 2 millim. broad, 
with muscular walls transversely striped. This passed into a long, 
narrow, coiled tube, which preserved the same calibre until it 
dilated into the stomach. ‘Two ample glands (salivary ?) entered 
the larger part of the tube on either side, but were not in any 
way fused with it. The liver was large and undivided behind. 
The central nervous system was enclosed in a thin capsule and 
somewhat concentrated, the cerebral and pleural ganglia being 
hardly distinguishable and the pedal ganglia lying beneath them. 
The eyes were large, black, and distinct. The genital mass was 
much hardened, but the two spermatothecs, one white and empty 
and the other black and full, were quite distinct. It was impossible 
to ascertain whether the glans was armed with hooks and whether 
the folds on the dorsal wall of the pericardium (sometimes called 
the pericardial gill) were present, but it is highly probable that 
the species possesses these family characteristics. 
In virtue of its buccal apparatus this animal belongs to Bergh’s 
genus Phyllidiopsis, although the tentacles are not attached 
through their whole length and are rather larger than is usual in 
the Phyllidiade. It is remarkable that the genus Phyllidiopsis 
contains one species, Ph. papilligera, which has also black papille 
on the back. To me, the presence of these dorsal papille seems a 
peculiarity sufficiently marked to merit generic rank. If Hchino- 
doris is a genus, why should not Phyllidiadze which have the same 
peculiarity enjoy the same distinction? I would propose to call 
the genus Ceratophyllidia, and its characters will be :—Back 
studded with papille ; buccal apparatus in the known species 
similar to that of Phyllidiopsis. 
PLEUROPHYLLIDIELLA HORATII, gen. et sp. nov. 
One specimen from Wasin, East Africa. Mr. Crossland, who 
captured it, gives the following notes on the living animal :— 
“Three inches long. Mantle edged with light salmon-colour; it 
