PLATE L. 



Inucei;a3I l f< {colli ill II ed) . 

 Figs. 



1— C. I. hililatus {HMoih.). Middle Chalk. (P. 281.) 



1. Lowilily uukuowu. Biitisli Musciuii, No. L209-13. Left v;ilve. 

 2, 3. Ea.-.tboiii'ue. Sedgwick Museum. 2, Lfl't valve. 3. Eight valve. 



4. Zone of BhijnchoneUa Cuvieri, Blauc Nez, Tas de Calais. Sedgwick 



Museum. Hiuge aud anterior margin of right valve. 



5. Plumpton. British Museum, No. 58GI. Tlie specimen figuied by Mantell, 



Foss. S. Downs, pi. xxvii, fig. 3, p. 216. Kight valve. 

 i>. Middle Chalk, near Warminster. Dr. Blackmore's Collection. Kight 

 valve. 



