PAs, ee 
Genus—PLEUROMYA, Agassiz. 
Fiaes. 
1,2. P. Orbigniana (Rouiller). Spilsby Sandstone, Donnington. Sedgwick 
Museum, Cambridge. la, right valve; 10, dorsal view. 2, orna- 
mentation X 12; a, near middle of valve; 0b, near the ventral 
margin; ¢, between a and b. (P. 256.) 
Genus—LtiopistHa, Meel:. 
3,4. LD. (Psilomya) gigantea (Sow.). Upper Greensand, Blackdown. Sedgwick 
Museum. 3a, left valve; b, hinge of the same. 4, umbo of right 
valve <6: “(Ps 257. 
5. I, sp. Red Limestone, Hunstanton. British Museum, No. 83628. 
a, right valve; b, dorsal view ; c, ornamentation x 6. (P. 258.) 
Genus—Cuspiparia, Nardo. 
6. CU. Sabaudiana (Pict. and Camp.). Gault, Folkestone. Museum of 
Practical Geology, No. 23821. a, left valve x 13; 0b, dorsal view 
i (Be 2o9;) 
