Cambrian Rocks in Cape Breton. 463 



of a fine punctation and of longitudinal strife on the middle 

 part of the valve. 



Size. — Length of a 'carapace, o|- mm. ; width, 3^^ mm. ; 

 depth, 2\ mm. 



Horizon and Locality. — In fine gray shale in the midst 

 of the volcanic rocks of the Colclbrook group at Dugald 

 Brook. Scarce. 



Indiana lippa, n. sp. PI. II., figs. 10 « to d. 



Hinge line more than half of the length of the valve- 

 Cardinal curves of moderate length ; anterior marginal 

 curve twice as long as the posterior, convexly arched. A 

 very faint elevation in the position of the ocular tuberclef 

 and a very shallow depression behind it. There is a thick- 

 ened and slightly elevated band all around the margin, 

 except at the hinge. 



Sculpture. — ^The surface has been corroded, but there is 

 a fine and rather distant punctation showing on one 

 example ; this becomes very fine towards the hinge-line, 

 where anastomosing ridges are developed, running off 

 toward the posterior slope of the valve. 



This species differs from the type of the preceding in 

 its more elongate form, greater plumpness and obscure 

 ocular tubercle. 



Size. — Length, 4J mm. ; width, 2| mm. ; depth, 2 mm. 



Horizon and locality. — Assise E. 3 /, Upper Etchemin- 

 ian, at Dugald Brook. Infrequent. 



SCHMIDTELLA. 



The two species referred to this genus are provisionally 

 so placed, because they are tumid toward the hinge, and an 

 ocular tubercle has not with certainty been observed. The 

 broad valve, somewhat pointed below, however, is not a 

 usual character of Schmidtella, and the valves are larger 

 than is usual in that genus. If the tubercle were present 

 the following species might be included in Braclorona 



