(_d_) In Guadeloupe we find _Cyclophorus_, _Amphibulimus_, _Homalonyx_, and _Pellicula_, which are characteristic of S. America, and nearly all recur in Dominica and Martinique. These islands are the metropolis of _Dentellaria_, a group of _Helix_, evidently related to some of the forms developed in the Greater Antilles. Stragglers occur as far north as St. Kitt’s and Antigua, and there are several on the mainland as far south as Cayenne. Traces of the great _Bulimus_, so characteristic of South America, occur as far north as S. Lucia, where also is found a _Parthena_ (San Domingo and Porto Rico). Trinidad is markedly S. American; 55 species in all are known, of which 22 are peculiar, 28 are common to S. America (8 of these reach no farther north along the islands), and only 5 are common to the Antilles, but not to S. America. The occurrence of _Gundlachia_ in Trinidad has already been mentioned. _The Bermudas_ show no very marked relationship either to the N. American or to the West Indian fauna. In common with the former they possess a _Polygyra_, with the latter (introduced species being excluded) one species each of _Hyalosagda_, _Subulina_, _Vaginula_, and _Helicina_, so that, on the whole, they may be called West Indian. The only peculiar group is _Poecilozonites_, a rather large and depressed shell of the _Hyalinia_ type. (2) =The Central American Sub-region= may be regarded as extending from the political boundary of Mexico in the north to the isthmus of Panama in the south. It thus impinges on three important districts--the N. American, West Indian, and S. American; and it appears, as we should perhaps expect, that the two latter of these regions have considerably more influence upon its fauna than the former. Of the N. American Helicidae, _Polygyra_ is abundant in Mexico only, and two species of _Strobila_ reach N. Guatemala, while the Californian _Arionta_ occurs in Mexico. S. American Helicidae, in the sub-genera _Solaropsis_ and _Labyrinthus_, occur no farther north than Costa Rica. Not a single representative of any of the characteristic West Indian Helicidae occurs. _Bulimulus_ and _Otostomus_, which form so large a proportion of the Mollusca of Venezuela, Colombia, Ecuador, and Peru, together with _Orthalicus_, are abundant all over the region. Again, _Cylindrella_, _Macroceramus_, and some of the characteristic Antillean operculates, are represented, their occurrence being in most cases limited to the eastern coast-line and eastern slope of the central range.