Hydroids:—
1. Hydra vulgaris†§.
Polyzoa:—
1. ? Plumatella emarginata†§.
2. Pectinatella burmanica.
The most striking feature of this list is the evidence it affords as to the distinct character of the fauna of the Malabar Zone, a feature that is also remarkably clear as regards the Potamonidæ, one genus of which (Gecarcinucus) is peculiar, so far as India is concerned, to that zone. As regards the sponges we may note the occurrence of no less than three species of the subgenus Stratospongilla, which has not been found elsewhere in India except on one occasion in Mysore, and of a species of the genus Corvospongilla, which is unknown from the rest of Peninsular India and from the Himalayas. The genus Pectispongilla is only known from the Malabar Zone. Among the polyzoa the genus Fredericella[[D]] appears to be confined, so far as the Indian and Burmese fauna is concerned, to the Malabar Zone, and the same is true as regards the group of species to which Plumatella tanganyikæ, an African form, belongs.
A further examination of the list of Malabar species and a consideration of allied forms shows that the majority of the forms restricted to the Malabar Zone are either African or else closely allied to African forms. The genus Corvospongilla, except for one Burmese species, is otherwise peculiar to Tropical Africa; while Stratospongilla, although not confined to Africa, is more prolific in species in that continent than in any other. Spongilla (Stratospongilla) bombayensis has only been found in Bombay, the Western Ghats, Mysore, and Natal, and Plumatella tanganyikæ only in the Western Ghats and Central Africa. The genus Fredericella (which also occurs in Europe, N. America, and Australia) is apparently of wide distribution in Africa, while Lophopodella (which in India is not confined to the Malabar Zone) is, except for a Japanese race of the Indian species, restricted outside India, so far as we know, to East Africa.
A less definite relationship between the sponges and polyzoa of the Malabar Zone and those of countries to the east of India is suggested by the following facts:—
(1) The occurrence of the genus Corvospongilla in Burma;
(2) the occurrence of the subgenus Stratospongilla in Sumatra, China, and the Philippines;
(3) the occurrence of a race of Lophopodella carteri in Japan;
(4) the occurrence of a species allied to Plumatella tanganyikæ in the Philippines.
It will be noted that in each of these instances the relationship extends to Africa as well as to the Eastern countries, and is more marked in the former direction. The species of Stratospongilla, moreover, that occurs in Sumatra (S. sumatrensis) also occurs in Africa, while those that have been found in China and the Philippines are aberrant forms.