96 
JURASSIC, OR 
The ridges are very prominent, but narrower than the in¬ 
terstices, sharp-edged above, so as to be somewhat imbricated 
upwards; and their greatest curvature, quite a sharp bend, 
takes place along the middle of the disk; a circumstance 
which does not occur in the larger varietv. 
Both varieties occur in the same dark cherty nodules. 
MODIOLA.— 
Plate 23, fig. 3. 
I would not attempt to name a Mytilus, or Modlola. But 
this is far from unlike a species figured by the Abbe Stoppani 
in his Palseontologie Lombardi, from the Lower Lias. M. psil- 
onoti , Quenstedt, is the species here referred to. It is too 
broad posteriorly for our fossil, and the anterior side too small. 
Modiola anatinci , Smith, a Fuller's earth species, is the nearest 
British type. 
MYOPHORIA BLANF0RDI —N. Sj>. 
Plate 23, fig. 6. 
Compare M. wjlata, Emm. (Trigonia postern, Quenst.), Stoppani, 
Pal. Lomb., 3rd Ser., pi. 7, f. 4, 5 ■, and Lyrodon curvirostre, Goldf., 
pi. 135, f. 13. 
Triangular, moderately convex, rather thick as broad as 
long [Surface—?]. Posterior side much the largest, gently 
convex, divided by a strong carina (which is produced into a 
beak at the posterior angle) from the disk. Within this carina 
the posterior slope is first convex, then concave to the 
margin : the two areas being separated by a faint ridge. In 
front of, and close to the carina, the disk has one or two slight 
ridges. But no trace of outside ornament is left. 
The characters above assigned to the posterior area contrast 
with those of M. liassica, Stoppani, 1. c. figs. 6-10. Where 
ours is convex, the Italian species is concave, and vice versa. 
But M. wjlata, Emmr., does appear, from Stoppani's figure, 
to be very like ours in the cast: except that his description 
