494 axel a. olsson 



Explanation of Plate 21 



Figure Page 



1-la. Aequipecten (Leptopecten) velero (Hertlein) 165 



Right and left valves, whitened slightly, length 11.4 mm. Meanguera, 

 Gulf of Fonseca, El Salvador. California Academy of Sciences, 

 No. 17869. 



2-2c. Aequipecten (Pacipecten) tumbezensis (d'Orbigny) 164 



Fig. 2, left valve, natural, length 24.4 mm. Tumbez, Peru; Figs. 

 2a, 2b, whitened, length 26 mm. Zorritos, Peru; Fig. 2c, left 

 valve, natural, length 34.6 mm. Puerto Pizzarro, Peru. FRI 25610. 



3-3a. Pecten (Pecten) perulus, new species 158 



Fig. 3, a part of the right valve, whitened and enlarged to show 

 grooving of the ribs; Fig. 3a, right valve, length 32.4 mm. Manta, 

 Ecuador. Paratype. 



4. Pecten (Flabellipecten) sericeus Hinds 160 



Inside of flat valve; same as figure 3a, Plate 19. California Academy 

 of Sciences, No. 17715. 



5-5a. Ljropecten (Nodipecten) snbnodosus (Sowerby) 161 



Specimen from Mr. Lee Beil collection, length 94 mm. Pedro Gonzales 

 Island. Pearl Islands, Panama. 



6. Amiisium (Cyclopecten) pemomus Hertlein 168 



Flaya Marinero beach near Guanico, Panama. PRI 25611. 



