TH 



■n taoeetan- 



i-jsVigqmi i 



PLATE 1— Continued. 



Page. 



1^'ig. 14. DiSCINA LODKN8I8........ . „..^. ,...^. 22 



14 a, b, c, €■ Varieties of form of the dorsal valve.r^n .,il( ^iiltriw^ni bovIbt -jtiaeqiJ?- d ,<! ,* 



14 d.f. Ventral valves of the same species. . =v.- 



Fig. 15. DiSCINA THUNCATA i 23 



° ' B V .IR.. 



15 a. A dorsal valve of the natural size. 



15 6. The same enlarged. 



/, 1 r 1 I ' 



Fig. 16. DrsciNA minuta iJ.uvii.-i; 16 



16 a. A dorsal valve of the natural si ". 



16 A. The same enlarged. 



Fig. 17. DiSCINA ALLEOHANIA . . . 25 



17 a. The dors.'il valve of a large individual. [^ yi • j 

 17 6. A pn/fllc view of fig. 17 a. 



17 c- The ventral valve of the same species. 



Fig. 18. DiSCINA ORANDIS /.' 17 



18 a. A dorsal valve which is somewhat distorted. 



18 b. The interior of a ventral valve of the same species. 



