172 



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 one in its more 

 elongate form, greater plumpness and obscure ocular tubercle. 



Size. Length, 4^ mm. ; width, 2 mm. ; depth, 2 mm. 



Horizon and locality. Assise E. 3 /, Upper Etcbeminian, at Dugald 

 brook, Escasonie, N.S. Infrequent. 



SCHMIDTELLA. Ulrich. 



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 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 Bradorona. 



SCHMIDTELLA (?) PERVETUS, PL XIII, figs. 11 a to <. 



Schmidtella? pervetus n. sp. Nat. Hist. Sec. N. B. Bull. vol. iv., p. 206, pi. iv., figs. 3 a 

 to c. 



Can. Rec. Sci. Montreal, 1902, p. 464. 



Schmidtella (?) " Only the right (?) valve is known [others found since.] The valve is 

 moderately arched and without furrows, and its greatest fullness is in 

 the upper half. The hinge-margin, which is more than half of the length 

 of the valve, is straight and is formed by an infolding of the edge, which 

 is without a furrow. No marginal fold was observed. 



Sculpture. The surface is covered with minute pits, closely placed ; 

 the raised spaces between the pits become so prominent on the lowerpart 

 of the valve that the surface seems tuberculated, rather than pitted ; 

 toward the lateral and the lower edges these tubercles are arranged in 

 rows, so that there the valve seems covered with obscure ridges parallel 

 to the margin. At the opposite side of the valve, towards the hinge-line, 

 the pits become very fine, and the surface of the valve has a shining ap- 

 pearance. 



Size. Length, 3 mm. ; width, 2 mm. ; depth, 1 mm. 



Horizon and locality. In Assise E. 3 e. of the Upper Etchemenian, 

 Dugald brook. 



