188 BULLETIN OF THE 
Order LYOPOMATA. 
Famity CRANIIDZ. 
CRANIA Retzius. 
Crania Pourtalesii Dall. 
B. MOLLUSCA VERA. 
Ciass PELECYPODA. 
Famiry PECTINIDZ. 
PECTEN Miller. 
Subgenus JANIRA Schumacher. 
Janira hemicyclica Ravenel. 
Subgenus AMUSIUM Schumacher. 
Amusium Dalli Smith. 
Section Propeamustum De Gregorio. 
Amusium Pourtalesianum Dall. 
Amusium Pourtalesianum, var. striatulum Dall. 
Amusium Pourtalesianum, var. marmoratum Dall. 
Amusium cancellatum Smith. 
Amusium Hoskynsi Forbes.* 
Amusium Holmesii Dall. 
Amusium Sayanum Dall. 
Amusium alaskensis Dall.* 
Subgenus PECTEN s.8 
Pecten magellanicus Gmelin. 
Pecten caurinus Gould. 
Pecten nucleus Born. ° 
Pecten dislocatus Say. 
Pecten phrygium Dall. 
Pecten exasperatus Sowerby. 
Pecten ornatus Lamarck. 
Pecten antillarum Récluz. 
Pecten effluens Dall. 
