• PLATE 30. 



Fig. 1. 496. 1. Myalina mytiliformis. (Pag. 100.) 



1 a. The right valve of this species somewhat compressed, and having the anterior expansion broken off in 



part. 

 1 b. The right valve of another specimen, less compressed than the preceding. 

 1 c. A specimen preserving both valves, which are partially open along the cardinal line. The lower portion 



of both valves is broken off. 



1 d. The left valve of tlie preceding specimen, compressed so that it appears much narrower than its natural 



form. 



Fig. 2. 497. 20. Modiolopsis ovatus. ( Pag. 101.) 



2 a. The left valve of a specimen of ordinary size. 



2 6. The right valve (imperfect) of a large individual. 



Fig. 3, & 4 <z. 498. 21. Modiolopsis subcaeinatus. (P^S- 101.) 



3 a. A young individual of this species. 



3 b, c. The right valves of two individuals of medium size. 



3 d. The left valve of an older individual. 



4 a. This individual has nearly the same form as figs. 3 b and 3 c, but is more compressed, and concentric 



folds are not at all conspicuous. 



Fig. 4 b. 499. 9. Tellinomya elliptica. ( Pag. 102.) 



Fig. 5. Cypkicardia? {n. s.). (Pag. 102.) 



5 a. View looking upon the cardinal line. 



5 6. Lateral view of left valve, which is crushed, showing the outline of the right valve beyond. 



