230 



THE CANADIAN NATURALIST. 



[Vol. vii, 



ON SOME NEW OR LITTLE KNOWN FOSSILS 

 FEOM THE SILURIAN AND DEVONIAN ROCKS 

 OF ONTARIO. 



By E. Billing?, F.G.S. 



SILURIAN. 





\:r 







Fig. 1. — Aulocopina Granti. — A nearly pei-fect specimen. 

 " 2. — The summit of a larger specimen. 



(Both figures natural size. The triie characters of the surface 

 -cannot be perfectly represented by -wood engravings.) 



Genus Aulocopina (X. G.) 



In a box of fossils lately sent to the Geological Survey by 

 Major Grant, of H;imilton, there are se\reral specimens which 

 appear to me to belong- to a new genus of sponges. The most 

 perfect is of an elongate, ovate, or pyriform sh.ipe. The larger, 

 or upper extremity, is more or less concave, with a small circular 

 space in the centre, which appears to be the mouth of a tubular 

 cavity that penetrated inwards and downwards, along the verti- 

 cal axis of the sponge. I shall call it the '• osculum." From 

 its edges numerous small, irregular, sometimes branching ridges, 

 radiate outwards in all directions over the surface, and descend 

 the sides to the base. Several polished sections, through the 

 osculura, downwards, show that the centre, at least in the upper 

 half, was occupied by a large tubular canal, with smaller ones 

 branching from \ir. sides, outwards and downwards. This struc- 

 ture is only indicated by the dark colour of the material which 

 fills the canals, in contrast with the light grey chert, which con- 

 stitutes the mass of the fossil. 



This genus somewhat resembles Auhcop'ium in its structure, 

 but dilfers in having its whole surface covered with the rounded 



