Fig. 45.—Zoarium of Stolella indica on stem of water-plant (from Calcutta), × 6.
Geographical Distribution.—So far as we know, this species is confined to the Indo-Gangetic Plain. Major Walton found it at Bulandshahr in the United Provinces, and it is not uncommon in the neighbourhood of Calcutta.
Biology.—The zoaria of S. indica are usually fixed to the roots of duckweed or to the stems of other plants. They are often found together with those of P. punctata. A slight infusion of brackish water into the ponds in which it lives does not seem to be inimical to this species, but I have found it in ponds in which nothing of the kind was possible. It flourishes during the "rains" and, to judge from specimens kept in an aquarium, is very short-lived. Major Walton found it growing over a zoarium of Hislopia lacustris.
The zoaria of this subfamily are never dendritic but form gelatinous masses which, except in Australella, are cushion-shaped or sack-like. With the possible exception of Australella, they possess to a limited extent the power of moving along vertical or horizontal surfaces, but it is by no means clear how they do so (see p. 172). The statoblasts are remarkable for their large size, and it is noteworthy that Australella, which is intermediate in structure between the Plumatellinæ and the Lophopinæ, possesses statoblasts of intermediate size. The swim-ring is always well developed, and fixed statoblasts are unknown.
Only two genera (Lophopodella and Pectinatella) have been definitely proved to occur in India, but a third (Lophopus[[BK]]) is stated to have been found in Madras. Should it be met with it will easily be recognized by the upright position of its polypides when their tentacles are expanded and by the fact that the statoblasts never bear marginal processes.
Genus 3. LOPHOPODELLA, Rousselet.
Lophopodella, Rousselet, Journ. Quek. Micr. Club (2) ix, p. 45 (1904). Lophopodella, Annandale, Rec. Ind. Mus. v, p. 54 (1910).
Type, Pectinatella carteri, Hyatt.
Zoarium. The zoarium consists of a circular or oval mass of no great size. Polyparia do not form compound colonies.