PLATE XT. 
All the figures on this Plate are from specimens from Lummaton in my Collection. 
MacetuaniA Waurppornel, Davidson, sp. (Page 91.) 
Fia. 
1. Dorsal view of a large specimen, defective at the beak, enlarged. 1a, portion 
of surface, x 25. 
MaAGELLANIA, Psp. (Page 92.) 
2. Dorsal view of a specimen, enlarged, showing the low rounded ribs. 2a, 
lateral view. 20, portion of surface, x 25. 
MAGELLANIA JUVENIS, Sowerby, sp. (Page 93.) 
3. Dorsal view of a very large specimen, whose foramen is hidden by the matrix. 
3a, lateral view. 
CENTRONELLA viRGO, Phillips, sp. (Page 94.) 
4. Dorsal view of a specimen, enlarged, showing ribs in front. 4a, lateral view. 
4b, portion of surface, X 25. 
N.B.—In 46 I have not myself observed the definite ridges, but the artist states that he 
has carefully copied the shell. In any case the figure is askew. It should be turned 
backwards through an angle of 45°, so that its left-hand corner would become the top, and 
then it would represent a portion of the left side of the shell, and give some idea of the 
elegantly arching system of puncta. Similarly la and 2a represent the artist’s views, and 
not my own. 
ENantiospHEN Vicaryi, Davidson, sp. (Page 97.) 
5. Dorsal view of an elongate specimen, showing the beak. 5a, lateral view. 
6. Dorsal view of a very wide specimen; fragments of shell having been 
removed from the apex of each valve show the beginning of the internal 
septa; the coarse prismatic structure of the shell-substance, where some- 
what decorticated, is also seen. This specimen is deep, and, when viewed 
laterally, it closely resembles fig. 5a. 
7. Fragment of the beak of a specimen seen laterally from within, and showing 
on the left the flat septum, to which is attached the convex dental plate 
which is seen on the right. 
ENANTIOSPHEN CHHLERTH, nov. var. (or n. sp.).. (Page 98.) 
8. Dorsal view of a very large specimen, perhaps only a variety of H. Vicaryi, 
having no marginal inflation. A portion of shell removed from the apex 
of the dorsal valve has exposed the beginning of the internal septal plate. 
8a, ventral view showing the prismatic structure of the shell where worn, 
and the transverse ridges where the surface is perfectly preserved. 8), 
lateral view showing the sharp margins of the area in both valves, and the 
transverse lineations. 
