West India Zand Shells, 



On the Geographical Distribution of the Genera and Species 

 of Land Shells of the West India Islands ; with a Catalogue 

 of the Species of each Island. 



By Thomas Bland. 



Eead, June 17, 1861. 

 Eeprmted from the Annals of the Lyceum of Natural History, New York. 



The researches carried on, especially daring the last fifteen 

 years, have developed the extraordinary richness in Land Shells 

 of the West India Islands. To the late Professor C. 13. Adams 

 helongs to a great extent the merit of directing the attention of 

 !N^aturalists to the subject, and it has, since the result of his first 

 visit to Jamaica was published, been zealously followed up. 



The West Indies consist of a curvilinear chain of islands 

 extending in a south-east and then southerly direction from the 

 coast of Florida in ISTorth America, to the Gulf of Paria, on the 

 east coast of Yenezuela in South America. The portion of the 

 Atlantic Ocean, in a manner inclosed by these islands and the 

 shores of the adjacent continents, is divided into two great 

 basins — the Gulf of Mexico and the Caribbean Sea. The for- 

 mer is separated to a considerable extent from the latter by the 

 Island of Cuba, the western end of which lies about midway 

 between Florida and the peninsula of Yucatan ; the distance 

 from the island to Florida being about 140, and to Yucatan 

 about 120 miles. The Gulf of Mexico is about 1000 miles long, 

 and has an average width of 650, or thereabouts. The Carib- 

 bean Sea is in length 1400, and in width at the narrowest 

 part about 400 miles. 



The islands are divided into three groups, viz. the Bahamas, 

 the Great Antilles (Cuba, Jamaica, Hayti, and Porto Rico), and 

 the Lesser Antilles ; the area of the first group is estimated to 

 be 5,424, of the second 75,638, and of the last, 4;,%1 square 

 miles. Of the great Antilles, Cuba, with the Isle of Pines, 



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