PLATE XXVII. 
Genus—Prcren, Miller. 
Pecten (Syneyclonema) orbicularis, Sow. (P. 145.) 
(All in the Woodwardian Museum, except fig. 4.) 
Fias. 
1,2. Tealby Limestone, North Willingham. Right valves. 
3. Gault, Folkestone, Wiltshire Collection. Right valve. 
4. Var. haldonensis, Woods. Upper Greensand, Kinegskerswell. Museum of 
Practical Geology, No. 991. Right valve. 
5. Chloritic Marl, Maiden Bradley. Right valve. 
6—9. Upper Greensand, Ventnor. 6, right valve (ears partly drawn from 
another specimen); 6, antero-ventral portion of the same X 3. ¢a, 
right valve (margins of ears slightly restored) ; 7, posterior portion 
of the same X 3; 7c, left valve of the same specimen. 8, right valve. 
9a, right valve; 9b, postero-ventral portion of the same x 5. 6, 7, 
Leckenby Collection. 8, 9, Wiltshire Collection. 
10—15. Chalk Marl, Burwell. 10a, left valve; 10%, portion of the same near 
the ventral margin X 10 (on other parts of the valve the fine concentric 
ridges are closer together). 11—13, right valves. 
14. Totternhoe Stone, Burwell. Part of interior of right valve x 2. 
