106 



ROYAL SOCIETY OF CANADA 



is no f^round for tliis except a rtwttiiihiance in j^eneral form. The struc- 

 tures, 80 far U8 known, are quite different. 



Note. — The two followin<^ species, haviiiy; the rows of spicules diac^on- 

 ally arranged, as I reinarl<ed in descrihini!; tlioni in 1889, have been 

 placed l)y Rauif in a new genus DiagonieUa. I doubt the expeciiency of 

 this on the mei"o ground of divergence of the nnvs of meshes from 

 horizontality. But there ai-e other peculiarities of these species, which 

 might fairly entitle them to constitute distinct sections of the genus. I 

 tlierefore, place them by themselves, noting these differences : 



5. — Protosponoia coronata, Dawson. 

 (Figs. 13, 14 and 15. PI. II.. Figs. 5 and 6.) 



Fig. I'A.—Protoapongia coro- 

 nata. Restored. 



Fig. U. 



-Protospongia coronata. Primary, second- 

 ary and protective .spicules, x 5. 



Body ovate, 2 cm. long, but fragments indicate that it grew much 

 larger ; spicules coai-se and four-rayed, so cimnected as to give the appear- 

 ance by their oblic^uity of a diagonal network of rhombic openings. This 

 may possibly be the effect of flattening. Numerous small cruciform flesh 

 spicules. Eoot spicules strong, short or bi-oken off, 2 to 4. Osculum 



>-^^^^ 



Fig. 15.- 



-Protospongia coronata. Showing 

 internal cavity. 



large, ter'ainal, covered with a conical hood made up of curved spicules 

 converging to a point, and 1 cm. in height, in \he smaller specimens, in 

 which alone I have seen them, the larger specimens being usuallj' imper- 

 fect. Short protective spicules visible at the sides. 



