185 



described from the Lower Silurian Rocks of Canada, in having the glabella 

 more obtusely rounded in front, and in the remarkable characters of the 

 surface, which is reticulated, all over the head, by the sharp lines separat- 

 ing the angular punctures ; while in H. antiquatus the glabella is smooth or 

 only minutely punctured. 



Dedicated to Mr. Wm. Denton, of Painesville, Ohio, who discovered it. 



Locality and Formation. Ottawa ; Trenton limestone. 



STENOPORA HURONENSIS. (N. sp.) 



Description. Corallines forming large rounded masses, sometimes one 

 foot in diameter and nine inches in height, covered with small conical ele- 

 vations from two to four lines in diameter, the most prominent about two 

 lines in height, and being distant from each other from one to six lines, 

 (measuring from the centre of each). The tubes are small, there being 

 about four or five in the width of one line, larger on the summits of the ele- 

 vations, where, also, they exhibit a tendency to an arrangement in lines 

 radiating from the apex of the elevations. In some of the weathered sec- 

 tions an obscure lamellar concentric structure is exhibited, similar to that 

 of Stromatopora concentrica. 



Locality and Formation. Cape Smyth, Lake Huron ; Hudson River 

 formation. 



Collector. R. Bell. 



5. New Species of Fossils from the limestones of the Quebec Group 

 from Point Levis and other localities in Canada Hast. 



ORTHIS BATTIS. (N. sp.) 



Description. Shell of medium size, semi-elliptical; hinge line about 

 one-fourth more than the length ; cardinal angles varying from about 80 

 to 90 ; sides straight and either parallel or a little converging for one-half 

 or three-fourths the whole length ; anterior angles and margin rounded ; 

 ventral valve with the umbonial region narrowly convex ; much compressed 

 towards the cardinal angles ; a deep rounded mesial sinus one-third the 

 whole width and dying out at about half the length from the front margin ; 

 sometimes an incipient fold in the middle of the sinus ; area low ; beak 

 minute, a little depressed below the umbo. Dorsal valve moderately con- 

 vex, with a short mesial fold corresponding to the sinus in the other valve. 

 Surface with fine striae apparently four or five in one line with indications 

 of concentric striae. 



