42 



DAWSON AND HINDE 



4. — Protospongia polynema, S.N. 

 (Figs. 11 and 12. PL III, fig. 5.) 



This is a large sponge in great shapeless flattened patches, several inches in diameter 

 though there are smaller individuals also. Body spicules fine and slender, making a very 



Fig. 11. — Protospongia polynema. Portion 

 of base of large specimen. 



open mesh. At base numerous simple root spicules, short, and, in some cases, expanded 

 at their extremities. Young individuals seem to have been globular and probably sessile, 

 while large individuals had a flat base, but the general form is greatly obscured by crush- 

 ing, especially in the larger specimens. 



Fig. 12. — Protospongia polynema. Primary, secondary 

 and tertiary spicules, x 5. 



It may be a question whether two species may not be included under the above 

 specific name. The larger specimens have much more open meshes while the smaller 

 are more hispid. These differences may, however, depend on age. I have attempted 

 only a partial restoration of this species in fig. 11, as the specimens do not show with 

 certainity the form of the upper part, which I imagine, however, had long protective 

 spicules. 



