PLATE VI. 
Genus Arca, Lamarck. 
FIGS. 
1—3. A. Dupiniana, d’Orb. (P. 32.) 
1, 2. Perna-bed, Atherfield. Leckenby Collection. Woodwardian Museum. 1a, right 
valve; 1, dorsal view of same specimen ; 2, hinge of left valve x 15. 
3. Ferruginous Sands, Shanklin. Collection of C. J. A. Meyer. Ornamentation on 
the right valve near the ventral margin below the umbones x 3. 
4,5. A. Carteroni, VOrb. (P. 33.) 
4. Lower Greensand, Upware. Woodwardian Museum. a, left valve; 4, anterior 
view ; ¢, dorsal of same specimen. Figured by Keeping. 
5. Atherfield Beds, East Shalford. Collection of C. J. A. Meyer. a, left valve; 
b, hinge and area of same x 1}; ¢, ornamentation, from the anterior part of 
the valve, x 3. 
6, 7. A. Sancte-Crucis, Pict. and Camp. Lower Greensand, Upware. 
Woodwardian Museum. (P. 34.) 
6. a, left valve; b, outline of anterior end; c, dorsal view of same specimen. (The 
right umbo and the anterior part of the area are partly obscured by adhering 
rock.) 
7. a, vight valve; 0, dorsal view of same specimen; c, ornamentation x 2. 
Genus BarBAtIA, Gray. 
8, 9. B. aptiensis (d’Orb.). Crackers, Atherfield.  Leckenby Collection, 
Woodwardian Museum. (P. 35.) 
8. a, left valve; b, dorsal; c, right valve; d, anterior; e¢, part of left valve near the 
mid-ventral margin xX 3. 
9. a, left valve; b, right valve. 
