11 



INTRODUCTION 



Some fifth of a century ago when I first saw a Florida beach, 

 with its multitudes of shells they seemed worthy of attention only 

 as adding variety to the general attraction of the seashore; but 

 within a few tides times the lion's paw, the angel's wing, the fight- 

 ing conch and the calico shell had acquired individuality and stimu- 

 lated an interest that must enrich any experience which includes 

 them. 



The abundance and variety of southern Florida's molluscan 

 fauna is unexcelled by any other in America, and by but few areas 

 of like extent anywhere. This circumstance is due to a combination 

 of ecological factors related to latitude, sufficient bathymetric range 

 for slight differences of water temperature, characters of sea bottom, 

 and some local modifications of salinity due to drainage of fresh water 

 from the Okeechobee basin and other areas. The littoral region has 

 many general characteristics of sand, mud and weedy bottom. Oyster- 

 bars, sandbars and mangrove flats, and in deeper water, rock and 

 coral reefs and outcroppings of hardpan have their peculiar associa- 

 tions of mollusks and other marine animals. Species native to a more 

 southerly province overlap some which have a more northerlj^ range, 

 and some genera common on the southern Atlantic Coast are es- 

 tablished along the Gulf Coast without continuity of any of their 

 species around the southern tip of the Florida Peninsula. 



All descriptions apply to specimens which were taken alive or 

 in such fresh and perfect conditions that a local station may rea- 

 sonably be assumed. All measurements refer to average sizes, adult 

 shells, and all illustrations are of recently collected specimens. 



The study collection upon which the descriptions are based has 

 been placed in the Thomas R. Baker Museum at Winter Park, 

 Florida. 



