Mr. I. J. Carter on the Freshwater Sponges of Bombay. 85 
of its structure, its radiated appearance interiorly, the form of its 
small spicula, and the manner in which its seed-like bodies are 
studded with little toothed disks ; and from the following species 
by the fineness of its texture and the spheroidal form of its seed- 
like bodies. Probably it is the species alluded to by Dr. John- 
ston* which was examined by Meyen from the kind and arrange- 
ment of the small spicula round the seed-like bodies, which how- 
ever in this species are not cemented together by carbonate of 
lime as stated by Meyen, but by an amorphous siliceous deposit. 
I have named it after Meyen, who has characterized it by the 
description of its minute spicula. 
5. Sp. plumosa, n. s.—Massive, surface convex, presenting 
gentle eminences and depressions, or low wavy ridges. Colour 
yellow. Growing in circumscribed masses, attaining a height of 
2 inches. Texture loose, coarse, resistent. Structure coarsely 
fibrous, reticulated, radiated, fibres fasciculated, spreading from 
the base towards the circumference in a plumose form. Seed- 
like bodies ovoid, about j,nd of an inch in their longest dia- 
meter, studded with little toothed disks. Spicula of two kinds, 
large and small; large spicula shghtly curved, smooth, pointed 
at each end, about ;',th of an inch in length; small spicula 
straight, sparsely spiniferous, terminated at each end by a toothed 
disk, about z4,nd of an inch in length. (Plate II. fig. 2.) 
Hab. Sides of freshwater tanks m the island of Bombay, fixed 
or floating, seldom covered by water more than six months in the 
ear. 
: Observations.—This is the coarsest and most resistent of all 
the species. As yet I have only found three or four specimens of 
it, and these only in two tanks. I have never seen it fixed on any 
solid body, but always floating on the surface of the water, about 
a month after the first heavy rains of the S.W. monsoon have 
fallen. Having made its appearance in that position, and having 
remained there for upwards of a month, it then sinks to the bottom. 
That it grows like the rest, adherent to the sides of the tank, 
must be inferred from the first specimen which I found (which 
exceeded 2 feet in circumference) having had a free and a fixed 
surface, the latter coloured by the red gravel on which it had 
grown. I have noticed it floating, for two successive years in 
the month of July, on the surface of the water of one of the two 
tanks in which I[ have found it, and would account for its tem- 
porary appearance in that position in the followimg way, viz. that 
soon after the first rains have fallen, and the tanks have become 
filled, all the sponges in them appear to undergo a partial state 
of putrescence, during which gas is generated in them, and ac- 
cumulates in globules in their structure, through which it must 
* Johnston’s British Sponges, p. 154. 
