PLATE XXIV. 



8pondylus spinosus (Sow.) (continued). (P. 127.) 



Figs. 



1. Upper part of M. cor-anguiimm zone, Mitcheldever. Dr. Blackmore's Col- 



lection, a, left valve ; b, posterior view. 



2. M. cor-anguiniim zone, Fletcher's pit, Gravesend. Woodwardian Mnseum. 



Small portion of left valve near the middle of the ventral border x 3. 



3. M. cor-anguinum zone. Hungry Down, Blandford. Woodwardian Museum 



(Coll. Mr. Jukes- Browne). Left valve, umbo slightly imperfect. 



4. Lower part of Mavsapites zone, Witherington. Dr. Blackmore's Collection. 



a, left valve ; h, section of ribs of the same near the mid-ventral border 

 X 2. 



5. Same horizon, locality, and collection, a, left valve ; h, section of ribs of left 



valve near the mid- ventral border x 2 ; c, posterior outline. 

 G. Marsupitefi zone, Margate. Dr. Rowe's Collection. «, right valve ; h, section 



of ribs of right valve near the mid-ventral border x 2; c, posterior 



outline ; d, viml)o of left valve x 5. 

 7. A. quadratus zone, West Harnham, Salisbury. Dr. Blackmore's Collection. 



Left valve. 



