EXPLANATION OF PLATE 9 

 All figures natural size 

 Fig. 1. Mytilus Tcewi, n. sp. Exterior of imperfect left valve. 

 Fig. 2a. Tivela trigonalis, n. sp. Exterior of left valve. 

 Fig. 2b. Tivela trigonalis, n. sp. Interior view of right valve. 

 Fig. 2c. Tivela trigonalis, n. sp. Interior view of left valve. 

 Fig. 3a. Chione elsmerensis English. Exterior view. 

 Fig. 36. Chione elsmerensis English. Interior view of left valve. 



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