FAUNAL RELATIONSHIPS. 81 
may occur elsewhere in the region. Its relationships are, of course, Mediter- 
ranean. 
Of the snakes Arrhyton with three species is confined to Cuba and proba- 
bly represents some Leptocalamus-like ancestor, modified through isolation. 
The Alsophis and Leimadophis are really West Indian, while the Boas, one 
Epicrates, and no less than four Tropidophes are typically Greater Antillean. 
The Typhlops is insignificant, being very wide-ranging and a type likely to be 
transported fortuitously. The fresh-water tortoise is found upon the four 
greater islands; Crocodylus acutus, although wanting in Porto Rico occurs on 
the other three. Crocodylus rhombifer is peculiar to Cuba and has but one near 
ally in C. moreletii of Central America; if this species ever proves to be any- 
thing more than rhombifer with a wrong locality label. 
The question of whether Cuba is a true continental island and whether 
or not it with the other West Indies has ever been joined together to form a 
far greater land mass than they do now, has been discussed elsewhere at length 
(see footnote p. 79). The discovery of fossil mammals, edentates, rodents, 
and an insectivore, unearthed in Cuba through Carlos de la Torre, Barnum 
Brown and the exploring parties from the M. C. Z., and the still more surprising 
collections made in Porto Rico by Franz Boas and Anthony and recently re- 
ported upon by J. A. Allen and Anthony, make it increasingly evident that 
this interpretation of the evidence of the amphibians and reptiles is the correct 
one. The significance of these fossil troves cannot be exaggerated and how 
much exploration remains to be done! A few years ago from densely populated 
and widely cultivated Porto Rico not a fossil mammal was known and some of 
the most learned palaeontologists did not postulate their presence there. Now 
several genera of rodents, an insectivore, and a sloth have been found and 
beyond doubt the end is not yet. Haiti is palaeontologically absolutely a terra 
incognita, or as perhaps we might better say in a paper upon Cuba, wna tierra 
desconocida. If suitable deposits are found, and if fortune favors, there is no 
great doubt but that a considerable mammalian fauna will be uncovered in the 
future. 
Perhaps the most interesting point which a study of the reptiles and amphi- 
bians brings out is that, although Cuba supports mainland types not found upon 
other islands, it has nevertheless in spite of the swift currents which sweep its 
shores and its proximity to Yucatan and Florida a typically West Indian fauna; 
those very forms being present in their reasonable proportion or representation, 
as so very many of them occur upon every island from Cuba to Grenada. It is 
