OF DENISON UNIVERSITY. 
79 
beaks rather prominent, incurved, situated over ^ from the front 
margin; ventral margin rather evenly curved; posterior margin ellip- 
tical; anterior margin curved abruptly below, but passing by a nearly 
straight line to meet the produced hinge at nearly right angles. The 
escutcheon is well defined by a strong post-umbonal ridge ; lunule 
well-marked. Greatest convexity near the middle ; surface covered 
with fine, close lines of growth. Length lo mm ; height 7 mm, 
thickness 4.5 mm. The state of preservation forbids positive identi- 
fication. 
Jfuculana iLeda) spatulata, sp. n. 
(Plate IX, Fig. ii, (12?) Plate VII, Figs. 35.) 
Shell elongate oval, broadly expanded anteriorly, acute behind; 
beaks small, slightly prominent, acute, about seven-twentieths the en- 
tire length from the anterior margin ; hinge-line rather strongly con- 
cave ; teeth (if present) small ; anterior margin forming a bold, uni- 
form curve, reaching nearly as high as the beaks, with its greatest an- 
terior projection above or near the middle; lower outline gently con- 
vex, nearlv attaining the hinge posteriorly, but separated from it by a 
short truncate posterior margin. Greatest convexity about one-third 
the height of shell from the beaks; umbonal ridge with a sudden, but 
gentle slope. The surface is marked by very numerous, fine lines of 
growth — about six occupying the space of i mm, in the shells meas- 
ured. Length [i] 20, [3] 17, [3] 16.5; height [i] 9, [2] 7, [3] 8; dis- 
tance from beak to front [i] 4, [2] 3, [3] 3 ; height of beak above 
longest transverse axis ]i] 7, ja] 6, [3] 5. From Leda bellistriata of 
the coal measures, which it greatly resembles, it differs in being more 
expanded anteriorly, and having the most convex part of the anterior 
margin higher than the middle. Shales below congl. 1 . It is possible 
that this is Dr. Stevens’ species, if so, however, its identification in the 
^coal-measures must be regarded as erroneous. 
J^uculana iLeda) similis, sp- n. 
(Plate IV, Fig. 15.) 
Shell large size, elongate, twice as long as high, rather flat; beak 
