PLATE XLVr. 



Figs. 1 — 2. OsTREA [Alectryonia] diluviana, Linne, p. 466; 1, 1 r/, 1 Zi, three views of a 



perfect specimen, the large valve was attached at the umbo with a large con- 

 cavity; 2, view of the lower valve which was grown to a rough surface nearly 

 by the whole face of the valve ; 2 a, posterior-view of the same specimen ; 

 1, from near Serdanmngalum ; 2, from Anapaudy, Trichinopoly grovp. 



Fig. ... 3. Plicatula instabilis, SfoL, p. 445 ; corrected figure of the specimen represented 



in fig. 8, pi. xxxiv. 



Fig. ... 4. OsTREA [Alectryonia] ctjpelloides, 5('o^.j p. 467 ; 4, 4a, 4i, anterior-, back- 



and inner-views of a lower valve ; Arrialoor, Arnaloor group. 



Figs. 5 — 6. Plicatula multicostata, Forbes, p. 466 ; 5, a specimen with a small place of 



attachment and very numerous, scabrous ribs; from near Ahmdanapooram ; 

 6, 6a, views of upper and lower valves, broadly attached and much depressed ; 

 from near Anapaiuly, Trichinopoly group. 



