510 axel a. olsson 



Explanation of Plate 37 



Figure Page 



1. Trachycardiiim (Trachycardium) consors (Sowerby) 245 



Length 52.8 mm., height 63.8 mm. Pearl Islands, Panama. PRI 25671. 



2. Trachycardium (Phlogocardia) belcheri (Broderip and Sowerby) 246 



Length 30.4 mm., height 37.4 mm. E'smeraldas, Ecuador. PRI 25672. 



3. Trachycardium (Dallocardia) senticosum (Sowerby) 246 



Length 54.7 mm., height 55 nun. Manta, Ecuador. PRI 25673. 



4. Mexicardia procera (Sowerby) 247 



Hinge and exterior. Length 90 mm., height 97 mm. Bayovar, Peru. 

 PHI 25674. 



5-5a. Papyridea mantaeusis, new species 250 



Fig. 5, length 40.5 mm., height 29.6 mm. Manta, Ecuador. Holo- 

 type, ANSP 218895; Fig. 5a, length 35.7 mm., height 25.5 mm. 

 Manta, Ecuador. Paratype, ANSP 218896. 



6-6a. Trigoniocardia (Trigoniocardia) biang'ulata (Broderip and Sowerby) 251 

 Exterior and interior, length 31.3 mm., height 29.9 mm. Pearl 

 Islands, Panama. PRI 25675. 



7. Acrosterigma pristipleura (Dall) 248 



Length 40 mm., height 52.5 mm. Isla Gorgona, Colombia. PRI 25676. 



8. Papyridea soleniformis aspersa (Sowerby) 249 



Length 29.9 mm., height 24.1 mm. Manta, Ecuador. P"RI 25677. 



9-9a. Trigoniocardia (Americardia) guanacastense (Hertlein and Strong) ....252 

 Fig. 9, posterior end view, height 54.4 mm., diameter 34.6 mm.; 

 Fig. 9a, exterior of a right valve, length 42 mm., height 55.1 mm. 

 San Pedro, Santa Elena, Ecuador. PRI 25678. 



