82 Memoirs of the Indian Museum. [Vol,. V, 



resembles that of M. schillerianum, except of course that there is no basal disk- 

 sphincter. The walls of the column are for the most part very thin, chiefly owing to 

 a reduction of the mesogloea, in this respect resembling those of the other Gangetic 

 species. In the region of the false physa (fig. 3A, p, 80) the endoderm is, however, 

 greatly thickened. 



Types. — Nos. Z.E.V. 6804-6/7, Ind. Mus. : from the vicinity of Calcutta. 



The species has not been found in the Chilka I,ake but occurs abundantly in 

 pools of brackish water at Port Canning in the Gangetic delta and in canals and 

 creeks near Calcutta. In the latter district it was on one occasion found in water of 

 a specific gravity of 1-006. 



P. gangeticus is distinguished from P. chilkaeus, the only other species as yet 

 known in the genus, mainly by its more numerous tentacles and by the lack of a true 

 sphincter ; other differential characters are shown in the table on the opposite page. 



At Port Canning P. gangeticus, which is markedly gregarious, is found in large 

 numbers ensconced in masses of the sponge Spongilla alba that have probably grown 

 round it on the roots of grasses. It is also found in the same pools in deserted bur- 

 rows of Teredo in wooden posts. In both situations it is lightly attached by its 

 degenerate basal disk to foreign bodies. Near Calcutta its favourite situation is 

 among the roots of reeds that grow at the edge of small tidal creeks. Here it is fre- 

 quently accompanied by masses of the polyzoon Victor ella bengalensis. Although it 

 is found in small holes in mud, I do not think that the anemone is able to burrow, 

 for in this situation it occurs actually attached to roots and accompanied by the 

 polyzoon, which certainly is not a burrower. In both cases the mud seems to be 

 deposited round the animal ; the anemone saves itself from suffocation by elongating 

 its column, while the colonial organism buds freely and so forms a dense mass prac- 

 tically impervious to mud, and is thus able to expand the tentacles of its individuals 

 upon the surface. At Port Canning I have seen an individual of P. gangeticus lying 

 exposed in the sun at the edge of a pool. The tentacles were retracted, the orifice above 

 them closed and the column fully expanded owing to the amount of water it contained ; 

 in the creeks near Calcutta large numbers of individuals may be found in mud between 

 tide-levels. Very few individuals found in winter are sexually mature ; probably the 

 real breeding-season begins about February. The species does not seem to be ex- 

 clusively nocturnal in habits. In an aquarium healthy individuals often cling to the 

 glass in an upright position by means of the mucus that exudes from the surface of 

 the column. They are able to drag themselves upwards by means of their tentacles 

 as well as to progress in a lateral direction. 1 



Phytocoetes chilkaeus, sp. nov. 



(Plate vii, fig. 2 ; plate viia, fig. 4.) 



This species, examined alive, resembles P. gangeticus very closely so far as the 

 external characters are concerned, except that it has not more than 24 tentacles 



1 For further details of this mode of progression see Rec. Ind. Mus. I, p. 67. 



