94 One Thousand Objects 



733. SPICULES OF GRANTIA (Grantia compressd). The 

 calcareous spicules of this sponge are (i) club-shaped, 

 curved at the thick end, and also (2) three-rayed, some- 

 times with one ray elongated. (PI. IX., figs. 26, 33, 45.) 



734. FRESH -WATER SPONGE GEMMULES (Spongilla 

 fluviatilis}. The green spherical gemmules of this sponge 

 bear some resemblance to a Volvox without internal 

 globes, and are sometimes plentiful in waters containing 

 the sponge. 



735. FRESH-WATER SPONGE SPICULES (Spongilla fluvia- 

 tilis}. The birotulate spicules of this sponge are a very 

 good example of this type of spicules. (PI. IX., fig. 44.) 



736. BOMBAY SPONGE (Spongilla Meyeni). The spi- 

 cules of the gemmules belonging to a fresh-water sponge 

 found in the tanks of Bombay are sold mounted by some 

 opticians, and are beautiful examples of birotulate spicules. 



737. RIVER SPONGE SPICULES (Spongilla lacustris). 

 This second species of British fresh-water sponge has 

 spicules straight, spindle-shaped, and also curved and 

 pointed at each end, both kinds being spiny. (PL IX., 

 fig- 36.) 



738. BRANCHED SPONGE (Chahna oculata}. One of 

 the commonest sponges thrown on the beach around our 

 coasts is this. A section of the sponge may be cut to 

 show its structure. The siliceous spicules are short, 

 straight, and pointed at both ends. 



739. SKULL SPONGE (Tethia craniutn). Sponge nearly 

 spherical. Spicules needle-like, pointed at both ends ; 

 others three-pronged, or recurved ternate ; others minute, 

 and hooked at each end. (PI. IX., figs. 27, 34.) 



740. STELLATE SPICULES (Tethia lyncuriuni). Sponge 

 globular. Spicules long, needle-shaped, pointed at each 

 end, collected in bundles; others stellate. Found in 

 several localities around the coast. 



741. CLUSTERED PARASITIC SPONGE (Leucosoleniabotry- 

 oides). Sponge cylindrical, branched, parasitic on sea- 

 weeds and zoophytes. Spicules three-rayed. 



742. CRUMB OF BREAD SPONGE (Halichondria panicea}. 

 Sponge variable, enveloping seaweeds or zoophytes, or 



