94 On new Species of Strom atopora. 



3. Stromato2)07'a granulata, Nich. PI. IV. tigs. 3, 3 a. 



Spec. char. Fossil forming thin crusts (usually about half 

 an inch in thickness) , often occupying very extensive surfaces. 

 Composed of concentric calcareous laminas, about ten in the 

 space of a line, separated by interspaces which are minutely 

 broken up into cells by numerous delicate vertical rods. 

 Surface regularly undulating, often raised into chimney-like 

 or conical elevations, which, however, are never perforated. 

 The entire surface is covered with a fine miliary granulation, 

 constituted by minute conical pustules, placed close together, 

 about one hundredth of an inch apart, and apparently imper- 

 forate. Exfoliated and broken specimens show that similar 

 granulated surfaces occur at small intervals throughout the 

 crust. 



Stromatopora granulata is nearly allied to S. tvherculata^ 

 from which, however, it can be readily separated, even in small 

 fragments. It is recognized by the much finer reticulation ot 

 the laminffi and vertical rods (PI. IV. fig. 3 a), and by the 

 minute crowded tubercles which cover the whole surface being 

 so closely placed as to be often nearly in contact. Though 

 many of the specimens shoAV larger or smaller crateriform 

 elevations, I have been unable to detect any perforations or 

 apertures in the surface. Usually the surface-layers exfoliate 

 round numerous points, giving the upper surface of the fossil 

 quite a characteristic appearance, which is wanting in S. tu- 

 herculata. One specimen observed by me covered a slab 

 about three feet in length by two feet in width, with an average 

 thickness of about half an inch. 



Loc. and Form. Not uncommon in a silicified condition in 

 the Corniferous Limestone (Devonian) of Port Colborne and 

 Savage's Quarry, Wainfleet, on the north shore of Lake Erie, 

 Canada West. Collected by the author. 



4. Stromatopora mammillata^ Nich. PI. IV. fig. 4. 

 Spec, cliar. Fossil forming thin crusts, about two or three 



lines in thickness, often covering extensive surfaces. Crust 

 composed of successive concentric calcareous laminae, separated 

 by interspaces, broken up by vertical rods. Surface un- 

 dulating, and exhibiting a series of large conical elevations, 

 about one fifth of an inch in height and the same in diameter 

 at the base, placed at distances apart varying from one fifth 

 of an inch to half an inch. Most of these conical elevations 

 show no signs of being perforated ; but some appear to have 

 apertures at their summits. The surface between these eleva- 

 tions is roughened by small tubercles and irregular ridges. 

 Nothing could be more distinct than the aspect of this very 



