550 axel a. olsson 



Explanation of Plate 77 



Figure P'age 



1. Mya arenaria Linne 422 



An enlargement of the dorsal margin of a left valve showing the 

 large chondrophoral plate; the small ridge (nymph) across it 

 divides the surface into two unequal areas, the wider section 

 behind the ridge is the resilifer, the smaller one in front of the 

 nymphal ridge is the attachment zone for the tensilium. New 

 Brunswick. 



2-2a. Cryptomya callfomica (Conrad) 423 



Fig. 2, exterior of a left valve, length 28.2 mm. Negritos, Peru. 

 PRI 25914; Fig. 2a, length 26.3 mm. Ventura, California. FRI 

 25915. 



3-3a. Tenuicorbula tenuis (Sowerby) 434 



Fig. 3, exterior of a left valve, length 20.6 mm. Venado Beach, 

 Panama Canal Zone. PRI 25916; Fig. 3a, dorsal aspect of a right 

 valve and shows the deeply excavated escutcheon. Length 22 mm. 

 Isla del Gallo, Colombia. PRI 25917. 



4. Condylocardia panameiisis Olsson 191 



Figure after Olsson, 1942. Length 1.75 mm. Pliocene, Punta Piedra, 

 south of Puerto Armuelles, Panama. 



5. Jnliacorbula elenensis, new species 438 



Length 17 mm. Santa Elena, Ecuador. Holotype, ANSP* 218913. 



6-6a. Hiatella solida (Sowerby) 425 



Fig. 6, length 28 mm., Mancora, Peru. PRI 25918A; Fig. 6a, 

 length 26.6 mm., Punta Ancon, Ecuador. PRI 25918B. 



7-7c. Taricorbula speciosa (Reeve) 438 



Length 18.2 mm. Gulf of Nicoya, Panama. Holotype, British 

 Museum (Nat. History). 



8. Sanguinolaria (Psammotella) bertinil Pilsbry and Lowe 349 



Length 72.3 mm., Tumbez, Peru. PRI 25928. 



9-9b. Sphenia fragilis Carpenter 424 



Figs. 9, 9a, length 8 mm.; Fig. 9b, length 6.8 mm. Venado Beach, 

 Panama Canal Zone. PRI 25919. 



10, 11. Sanguinolaria (Sanguinolaria) tellinoides A. Adams 348 



Fig. 10, length 67.7 mm. Isla del Gallo, Colombia. PRI 25920A; 

 Fig. 11, length 74.4 mm. Cojimenes, Ecuador. PHl 25920B. 



