PANAMIC-PACIFIC PELECYPODA 531 



Explanation of Plate 58 



Figure Page 



1-lc Mactra (Mactroderma) velata Philippi 322 



Fig. 1, enlargement of hinge; Figs, la, lb, length 67 mm., Mancora, 

 Peru. PRI 25795; Fig. Ic, length 68.5 mm. San Lorenzo, Santa 

 Elena, Ecuador. PRI 25796. 



2-2c. Mulinia pallida (Broderip and Sowerby) 330 



Fig. 2, length 28.5 mm., Old Panama, Panama. PRI 25798; Figs. 

 2a, 2b, length 17.7 mm., Panama City, Panama. PRI 25799; Fig. 

 2c, enlargement of hinge. 



3-3h. Slactrellona exoleta (Gray) 328 



Fig. 3, length 117 mm.; Fig. 3a, length 109 mm.; Fig. 3b, enlarge- 

 ment of hinge. Guanico, Panama. PRI 25800. 



4-4a. Mactra (Mactromeris) dolabriformis (Conrad) 323 



Length of a right valve 93 mm. Atacames, Ecuador. PRI 25801. 



