4 Dr. II. A. Nicliolson on the Genus Stromatopora. 



The Forest-bed Cervidffi taken as a whole, although com- 

 posed of a remarkable and peculiar assemblage of forms, show 

 us, as has been pointed out by Mr. Boyd Dawkins in the 

 valuable paper above mentioned, that the Forest-bed itself is 

 rather of Pleistocene than Pliocene age ; and as we know 

 that Elephas ijrimigenms^ E. anfi'qiais, and Bison ^''^-iscits, all 

 Pleistocene forms, are numbered amongst its fauna, we are 

 justly entitled to consider that the data are such as warrant 

 the above conclusion. 



II. — On the Affinities of the Genus Stromatopora, until Descrip- 

 tions of two new Species. By H. Alleyne Nicholson, 

 M.D., D.Sc, M.A., F.R.S.E., Professor of Natural History 

 in University College, Toronto. 



In the 'Annals' for August 1873 I described four species of 

 Stromatopora (one from the Upper Silurian, and three from the 

 Devonian rocks of Canada) , all of which exhibited certain re- 

 lationships with the Spongida. As regards two of the species 

 described in the paper alluded to, I have now obtained some 

 further material, by wliich certain interesting points of struc- 

 ture are brought out, and the reference of these fossils to the 

 Spongida is still more clearly established. I have also to de- 

 scribe for the first time two new and exceedingly interesting 

 species of the genus — one from the Corniferous Limestone 

 (Devonian), and the other from the Niagara Limestone (Upper 

 Silurian). In the first place, however, it may be as well 

 to discuss briefly the systematic position of the genus Stro- 

 matopora. 



The genus Stromatopora of De Blainville includes a number 

 of fossils of doubtful aflinities, which have the common cha- 

 racter of forming amorphous masses or irregular expansions, 

 composed of delicate calcareous laminae, arranged in successive 

 strata one above the other, and separated from one another by 

 minute vertical props, pillars, or dissepiments. Very often the 

 successive laminae are disposed round an imaginary centre or 

 centres in a concentric manner, giving rise to spherical, hemi- 

 spherical, or irregularly massive forms. In other cases the 

 mass * is extended so as to form an expanded cup or irregular 



* I would suggest that the term " sarcodeme " (Gr. sarx, flesh ; demos, 

 people) might advantageously be employed to designate the entire or- 

 jrauism or colony amongst the compound Foraminifera and the Sponges. 

 Some such term is certainly needed in treating of such problematical 

 org.anisms as Stromatojwra, of which the exact systematic position is 

 doubtful. 



