110 MA]!^UAL OF THE MOLLUSCA. 



the rainy wooded region that borders the Caribbean Sea. The 

 land snails of Central America resemble those of the Antilles 

 in the prevalence of some characteristic genera — Olandina, 

 Cylindrella and Helicina, — of which very few species are found 

 on the northern Coast of the Gulf of Mexico. The Bulimi are 

 numerous, but chiefly thin, translucent species. 



Helix 33 Glandinft 25 Cistula 7 



Proserpina 1 Tornatellina 1 Cyclophorus 3 



Bulimus 50 Pupa 1 Chondropoma 3 



Succinea 6 Cylindrella 20 Megaloma 2 



Acliatina(Spiraxis) .. 35 Cyclotus 1 Helicina 22 



Amongst the fresh-water shells are Neritina pida, Cydas 

 maculata, Corhicula convexa, and 7 species of Cyrena. From 

 Mazatlan, Mr. Carpenter describes Cyrena oUvacea and Mexicana, 

 GnatJiodon trigonus, Anodon ciconia (allied to the Brazilian 

 A. anserina), Fhysa aurantia and elata, .Planorhis sp. Melampus 

 oUvaceus. Two brackish-water sj)ecies, Cerithidium varicosum 

 and Montagnei, are common to South America. 



21. Antilles. 



The West Indian Islands have supplied nearly 500 species of 

 Helicidce, a larger number than any province except the Lusi- 

 tanian ; and above 260 Cydosfomidce, or nearly three times as 

 many as India. They are also richest in generic forms, and 

 the climate is highly favourable to the multiplication of indi- 

 viduals. The mean temperature of the Antilles is 59^ — 78®, 

 and the annual fall of rain exceeds 100 inches in most of the 

 islands. 



Helix ,.200 Pupa 26 Cj^cloplioms 1 



Stenopus 2 Cylindrella 73 Cyclotus 14 



Sagda 20 Clausilia 1 Megaloma 8 



Proserpina 5 Balea 1 Helicina 43 



Bulimus 53 Succinea 16 Alcadia 17 



Achatina 27 Chondropoma 15 Trocliatella 16 



Glandina 46 Clioanopoma 53 Lucidella 6 



Spiraxis 9 Adamsiella 10 Stoastoma 20 



Tornatellina 1 Cistula 86 Geomelania 21 



Probably every island has some peculiar sj^ecies, and those 

 of the great islands like Cuba and Jamaica are nearly all dis- 

 tinct. To Jamaica belong the species of Stoastoma, Sagda, and 

 Geomelania, the small sub-genus Lucidella, iho Alcadias and the 

 mass of beautiful Cyclostomas with a decollated spire and 

 fringed lip {Clioanopoma, Adamsiella, Jamaica, Chondropoma, 



