PEATE Xi: 
All the figures on this Plate are from specimens from Lummaton in my Collection. 
MEGANTERIS INORNATA, d@’Orbigny, sp.? (Page 95.) 
Fig. 
1. Ventral view of a large but rather crushed specimen, showing muscular impressions near the beak. 
la, dorsal view of the beak. 14, lateral view, showing the entire or almost entire absence of 
an area. 
STRINGOCEPHALUS Burtini, Defrance. (Page 96.) 
2. Dorsal view of the smallest specimen I have seen, enlarged. 2a, portion of surface, x 10. 
MeERrIstTa PLEBEIA, Sowerby, sp. (Page 98.) 
3. Dorsal view of a very large but distorted specimen, enlarged, showing the lines left by the 
edges of the internal septa. 34a, lateral view. 
4, Dorsal view of another specimen, enlarged, in which a portion of shell near the apex of the dorsal 
valve has fallen out, and left the central septum and the two lateral arching plates exposed. 
4a, outline of front view. 
Cn 
. Natural section of another specimen, enlarged, showing one of the septa of the shoe-lifter process 
and the attached dental plate, and also the beginning of one of the spiral arms. 
MERISTA PLEBEIA, var. LACRYMA, Sowerby, sp. (Page 99.) 
6. Dorsal view of a specimen, enlarged. 6a, front view, showing the biplicated fold. 
Biripa ? PLANA,n. sp. (Page 102.) 
8. Dorsal view of a specimen, showing median depression, enlarged. 8a, lateral view. 8 6, diagram 
of beak magnified. 
Guassta WHIDBORNEI, Davidson. (Page 114.) 
7. Dorsal view of a flat specimen, showing growth-lines, enlarged. 7 a, lateral view. 
9. Dorsal view of a deeper specimen, enlarged. 9a, lateral view. 9 6, beak, more enlarged. 
CYRTINA H£TEROCLITA, var. DemMaRuit, Davidson. (Page 118.) 
10. Dorsal view of a specimen in which the central fold is bitid, but the plaits few and irregular as 
in Defrance’s shell. 
CYRTINA HETEROCLITA, Defrance, sp. (Page 111.) 
11. Dorsal view of a specimen in which the central fold is simple above and trifid near the margin, 
enlarged. 
12. Oblique ventral view of another specimen which has small oblique rays running down each side of 
the central sinus, enlarged. 
CyRTINA HETEROCLITA, var. MULTIPLICATA, Davidson. (Page 112.) 
13. Dorsal view of the specimen said to be figured by Davidson (vol. v, pl. ii, fig. 8), enlarged. 
13 a, side view showing the flat receding area of the ventral valve. 
