PLATE 50. 



Vag» 



pj j^_ Cypricardinia sublamellosa. 267 



1. The right valve, natural size. 



J.- 2. Cypricardinia concentrica. 



2. The right valve of this species. 



pj 3 Cypricardinia crassa. 



3. The right valve, natural size. The posterior side is somewhat broken and obscure. 



Yi„. 4. Megambonia lata. 



4. The left valve of this species. 



-pis.b. Megambonia oblonga. 



6. The left valve of this species. 



-£[„ 6. Megambonia cordifobmis. 



6 a Profile view from the anterior side of the shell. 



6 b. View of the right valve, having the posterior cardinal extension abraded. 



Fjg. 7, Megambonia ovata. 



7. The cast of the right valve. 



268 



268 



277 



277 



278 



279 



