PLATE XL. 
Proren (continued). 
5. P. (Neithea) quinquecostatus, Sow. (P. 202.) 
1. Cenomanian (Meyer's Bed 12), Dunscombe. Woodwardian Museum. Portion 
between two main ribs of right valve x 6. 
2. Upper Chalk (A. quadratus zone), West Harnham, Salisbury. Dr. Blackmore’s 
5 
—) 
Collection. a, right valve; b, anterior view; ¢, portion of right valve x 4. 
3. Upper Chalk, probably Sussex. British Museum, No. 74979. Right valve. 
4, Upper Chalk (? M. cor-anguinum zone), Gravesend. Bristol Museum. a, right 
valve; b, portion of the same between two main ribs x 4. 
. Upper Chalk, Sussex. British Museum (Dixon Collection), No. L. 14742. Right 
valve. 
Ox 
6,7. P. (Neithea) quadricostatus, Sow. (P. 210.) 
6. Upper Greensand (Chert Beds), Sutton Veny, Warminster. Woodwardian 
Museum. Posterior half of left valve. 
7. Upper Greensand, Warminster. Woodwardian Museum. Portion of right 
valve x 4. (The line near the middle of each furrow is accidental.) 
8,9. P. (Neithea) equicostatus, Lam. (P. 208.) 
8. Upper Greensand, Worbarrow. Museum of the Geological Society, No. 1530. 
a, right valve x 2; b, posterior view of the same x 2. 
9. Upper Greensand (Chert Beds, zone of P. asper), Haldon. Bristol Museum. 
a, right valve; b, anterior view of the same x 2; ¢, part of anterior ear of 
the same x 4. 
10—15. P. (Neithea) seacostatus, Woodw. Upper Chalk (A. quadratus zone), Kast 
Harnham, Salisbury. Dr. Blackmore’s Collection. Right valves, 
except fig. 12. (P. 214.) 
10a, x 14; 106, portion of same x 4; lla, x 13; 11 }, posterior view of the 
same xX 12; 12, left valve x 11; 13 a, natural size; 13 b, part of posterior 
view of the same x 2; 14a, x 13; 145, outline of the same, posterior 
aspect, natural size; 15, natural size. 
