Major J. Stephenson (Rec. Ind. Mus. v, p. 233) has recently found two other species of oligochætes inhabiting _S. carteri_ var. _lobosa_ from Travancore. Both these species, unlike _Chætogaster spongillæ_, belong to a genus that is vegetarian in habits. One of them, _Nais pectinata_, has not yet been found elsewhere, while the other, _Nais communis_, has a very wide distribution. The latter, however, occurs in the sponge in two forms--one with eyes, the other totally blind. The blind form (_N. communis_ var. _cæca_) has only been found in this situation, but the other (var. _punjabensis_) lives free as well as in association with the sponge, in which the blind form was the commoner of the two. The majority of the animals found in association with _S. carteri_ gain shelter without evident assistance to the sponge. This is the case as regards the little fish (_Gobius alcockii_), one of the smallest of the vertebrates (length about 1/2 inch), which lays its eggs in the patent oscula, thus securing for them a situation peculiarly favourable to their development owing to the constant current of water that passes over them. In the absence of sponges, however, this fish attaches its eggs to the floating roots of the water-plant _Pistia stratiotes_. Numerous small crustacea[AE] also take temporary or permanent refuge in the cavities of _S. carteri_, the most noteworthy among them being the Isopod _Tachæa spongillicola_[AF], the adults of which are found in the canal of this and other sponges, while the young cling to the external surface of the carapace of _Palæmon lamarrei_ and other small prawns. Many worms and insects of different kinds also enter the canals of _S. carteri_, especially when the sponge is becoming desiccated; from half-dry sponges numerous beetles and flies may be bred, notably the moth-fly _Psychoda nigripennis_[AG] of which enormous numbers sometimes hatch out from such sponges. [Footnote AE: According to the late Rai Bahadur R. B. Sanyal, freshwater sponges are called in Bengali "shrimps' nests." From his description it is evident that he refers mainly to _S. carteri_ (see Hours with Nature, p. 46; Calcutta 1896).] [Footnote AF: Stebbing, J. Linn. Soc. xxx, p. 40; Annandale, Rec. Ind. Mus. i, p. 279.] [Footnote AG: Brunetti, Rec. Ind. Mus. ii, p. 376 (1908).]