SYNOPSIS OF THE FAMILY TELLINID^E AND OF THE 

 NORTH AMERICAN SPECIES. 



By William Healey Dall, 



Honorary Curator, Divmon of Mollusks. 



In reviewing the family Tellinida?, as restricted })y me,^ for the 

 purpose of revising the American Tertiary species, so much work was 

 necessitated on the recent forms of our coast as to make it desirable to 

 record it for the benefit of students of the existing fauna. 



The present synopsis aims to include in the list of North American 

 species those which have been actually found on our coasts, exclusive 

 of Central America and the West Indies, excepting a few which it 

 seemed, for one reason or another, were likely to occur there, and 

 do occur in adjacent waters, and have therefore been inserted. No 

 attempt has been made to include a complete enumeration of the West 

 Indian or Panamic Tellinida?, though it is probable that a much largei' 

 number of them than is now known to do so will eventually be found 

 to reach our waters. The energetic researches of Mrs. Oldroyd and 

 other Californian collectors have already added a large number of 

 molluscan species to the fauna of San Diego and San Pedro, which 

 were previously recorded only from Mexico or Middle America, and 

 it is to be anticipated that thorough dredging will add largely to the 

 number. The northern limit of the Panamic fauna is Point Concep- 

 tion, California; its southern limit is probabl}^ in the vicinity of Payta, 

 Peru, where the Peruvian current strikes westward across the Pacific. 



Each coast boasts of over fifty species of Tellinida?, the Pacific coast 

 being slightly the richer, especially in the genus Macoitia. 



Pelecypods, being creatures living usually in moderate depths, are 

 well suited to give indications of faunal relations as modified ])y geo- 

 logical changes. A table of the species common to both coasts, or 

 represented by closely related analogues, will not ])e without interest. 



^ Transactions of the Wagner Free Institute of Science, III, Pt. 3, 1895. 



Proceedings U. S. National Museum, Vol. XXIIl— No. 1210. 



