216 

 LINGULA CYANE. (N. sp.) 



Fig. 200, a-d. 



Description. Shell small, sub-ovate or obscurely pentagonal. Ventral 

 valve longer than the dorsal ; beak acute : apical angle about 60 ; great- 

 est width below the mid-length ; the upper half uniformly tapering, with 

 nearly straight margins to the beak ; sides in the lower half gently con- 

 vex and sub-parallel ; anterior angles rounded ; a portion in the middle of 

 the front margin nearly straight. The dorsal valve is a little shorter than 

 the ventral, and more obtuse in the upper half. Both valves are rather 

 strongly convex, but slightly flattened along the median line from the mid- 

 length to the front margin. Surface with fine concentric striae scarcely 

 visible to the naked eye, and with a few larger undulations of growth. 

 One specimen, under the magnifier, shews fine radiating striae. 



Length of ventral valve 3J- lines ; width, 3 lines ; length of dorsal valve 

 3 lines ; width the same. 



Locality and Formation. P, four miles north-east from Portland 

 Creek, Newfoundland : Quebec group. 



Collector. J. Richardson. 



OTHER SPECIES OF LINGULA. 



L. QUEBECENSIS, ante, p. 72, occurs in Division P, on the south side of 

 Cow Head. 



ACROTRETA GEMMA. (N. Sp.) 

 a 6 



Fig. 201. Acrotreta gemma. The small outline figures indicate the natural size ; a and 

 c, dorsal valves ; b, ventral valve, as seen from above ; (/, area of a ventral 

 valve which shews a central groove : /, area of another specimen which ex- 

 hibits no groove ; e, side view. 



Fig. 201. 



Description. Shell very small, about 1 line in diameter ; one valve 

 nearly flat, and the other, acutely conical. Dorsal valve very gently con- 



