(_b_) _Jamaica._--The land Mollusca of Jamaica are, in point of numbers and variety, quite unequalled in the world. There are in all as many as 56 genera and more than 440 species, the latter being nearly all peculiar. The principal features are the Glandinae, the Helicidae, and the land operculates. The Glandinae belong principally to the sub-genera _Varicella_, _Melia_, and _Volutaxis_, _Streptostyla_ being absent, although occurring in Cuba and San Domingo. There are 10 genera of _Helix_, of which _Pleurodonta_ is quite peculiar, while _Sagda_ (13 sp.) is common only with S.W. San Domingo (2 sp.), and _Leptoloma_ (8 sp.) only with Cuba (1 sp.). The single _Strobila_ seems to be a straggler from a N. American source. _Macroceramus_ has only 2 species as against 34 in Cuba, and of _Cylindrella_, in which Cuba (130 sp.) is so rich, only 36 species occur. The genus _Leia_, however (14 sp.), is all but peculiar, occurring elsewhere only in the neighbouring angle of San Domingo, which is so closely allied with Jamaica. The complete absence of _Strophia_ is remarkable. [Illustration: FIG. 230.--Characteristic Jamaican and Haitian Mollusca: =A=, _Sagdae pistylium_ Müll., Jamaica; =B=, _Chondropoma salleanum_ Pfr., San Domingo; =C=, _Eutrochatella Tankervillei_ Gray, Jamaica; =D=, _Cylindrella agnesiana_ C. B. Ad., Jamaica.] The land operculates form the bulk of the land fauna, there being actually 242 species, as against 221 of land Pulmonata, a proportion never again approached in any part of the world. As many as 80 of these belong to the curious little genus _Stoastoma_, which is all but peculiar to the island, one species having been found in San Domingo, and one in Porto Rico. _Geomelania_ and _Chittya_, two singular inland forms akin to _Truncatella_, are quite peculiar. _Alcadia_ reaches its maximum of 14 species, as against 4 species in San Domingo and 9 species in Cuba, and _Lucidella_ is common to San Domingo only; but, if _Stoastoma_ be omitted, the Helicinidae generally are not represented by so many or by so striking forms as in Cuba, which has 90 species, as against Jamaica 44, and San Domingo 35.