EXPLANATION OF PIRATE IV. 



Figs, i t ia t 2. Spongilla alba, Carter. 



i, la. Fragments of the skeleton of a very hard specimen from a rock in the 

 Chilka Lake, x 50. 



The preparations had been cleaned and stained with pyrogallic acid to show the horny substance. 

 Some of the single spicules forming the subsidiary skeleton may be noted in situ. 



2. Fragments of the skeleton of a very soft specimen from weeds in a pond 

 on Barkuda Id., treated in the same way, x 50. 



Fig« 3« Spongilla nana, sp. nov. 

 A complete sponge stained with borax carmine and mounted in Canada balsam, 

 seen from below, x 15. 



c.c. — central cavity, s.c. — subdermal cavity, g. — gemmule. 



Figs. 4, 4a. Suberites sericeus, Thiele. 



4. Vertical section through the skeleton of a sponge in the more vigorous 

 phase, x 15. 



4a. Fragments of the skeleton from the interior of the same sponge in the 

 neighbourhood of an engulfed colony of the hydroid Bimeria fluminalis, more highly 

 magnified. The preparation has been stained with pyrogallic acid. 



s.f. — vertical spicule-fibres on the surface of the sponge, i.e. — the position of one of the main 

 horizontal canals, b.m. — horny basal membrane. 



Figs, 5, 6, 6a„ Laxosuberites aquae-dulcioris (Annandale). 



5. Type-specimen on an oyster-shell from Manikpatna in the outer channel of 

 the Chilka L,ake, x 2. 



6. A single branched spicule-fibre in lateral view, x 100. 



6a. A fragment of the skeleton in the neighbourhood of a large vertical and a 

 superficial horizontal canal, x 75. 



v.c. — position of vertical canal, h.c. — position of horizontal canal. 



Fig. 7. Cliona vastifica, Hancock. 

 Part of an oyster-shell from the Manikpatna beds destroyed by the sponge, x 1. 



