Cambrian Rocks in Cape Breton. 459 



furrow extending from it on the cardinal slope of the 

 valve. The valve is most tumid toward the posterior (?) 

 side ; and the ventral angle is vertically behind the end of 

 the cardinal line. A broad thickened band runs around 

 the supposed posterior margin. 



Sculpture. — The shell is minutely pitted, but it is mostly 

 decorticated. 



Size. — Length, 3 mm. ; width, oh mm. : depth, f mm. 



Horizon and Locality. — Assise E. 1 d. Lower Etche- 

 minian, at Boundary Brook. 



EscASOXA (??) INGENS, n. sp. PI. II. figs. 7 a to c. 



Only one valve known. The unusual form agrees with 

 none of the other genera of the Etcheminian Ostracods. 

 It appears to be a left valve and is so described here. 

 The outline is obliquely subtriangular and somewhat wider 

 than long. 



The hinge line is three-quarters of the length of the 

 valve ; a shallow furrow runs parallel to the hiuge, and 

 near it for two-thirds of the length of the valve. No 

 ocular tubercle could be detected, but at what appears to 

 be the posterior upper angle of the valve is a small 

 tubercle. The anterior cardinal curve is short and nearly 

 in the direction of the hinge; the posterior is wanting. 

 The anterior marginal curve is long and strongly arched ; 

 the posterior is shorter and less arched, abruptly rounded 

 below, and at a right angle with the hinge line. The 

 valve is highest at the middle, gently arched toward the 

 hinge, and to the lower margin of the valve, and more 

 abruptly towards the anterior margin. A faint ridge or 

 swelling runs along the back of the valve near the margin. 

 Lower angle of the valve bluntly rounded. Traces of a 

 narrow marginal fold are preserved in some places. 



Soalpture. — The surface is corroded, and only in a few 

 places can a fine punctation be seen. 



Size. — Length, 6 mm. ; width, 6| mm. ; depth, 1;^ mm. 



