INTRODUCTION. 215 



of rats was derived from the race which inhabits Jamaica {C. melanurus) the original progeni- 

 tors of the Swan Island species must have drifted o\er a sea space of at least three hundred 

 and twenty miles; for Swan Island h!es exactly that distance in an almost due westerly direc- 

 tion from the nearest point of Jamaica, along the course of the Gulf Stream. The genus is 

 not found on the mainland of Honduras, ninety-eight miles to the south, which puts this 

 comparatively short sea-route out of court. 



For the sake of those who may not have given such a subject a thought, we might add 

 that a journey of this nature across an open sea could only have been rendered possible by 

 the rats having l)een carried out to sea liy means of a floating island of vegetation, or a mass 

 of entangled tree-trunks such as one often sees in mangrove swamps." 



This entire account is so inaccurate that one's confidence in the author's 

 interpretations and observations in geology are sadly shaken. This creature 

 which is in no wise related to the rats except that it is a rodent, is not like C. 

 melanurus which also, is not found on Jamaica. C. hrowni is the Jamaican form, 

 a wholly distinct species now rare owing to mongoose ravages. C. melanurus 

 is a long-tailed species from the high mountains of eastern Cuba. In Cuba two 

 other species, C. pilorides and C. prehensilis, are abundant, the former extremely so. 

 The genus is not, except for the Swan Island species, confined to the Greater 

 Antilles, but a species, C. ingrahami, is found in the grass of one of the small low- 

 lying Plana Keys of the southern Bahamas. It is mathematically improbable 

 that an island of vegetation set afloat from a country like Jamaica where there are 

 no rivers capable of performing this relatively rare phenomenon would be in- 

 habited at the same time by a hutia. The island would also have to steer very 

 carefully to meet Swan Island which is very small, and even granting that there 

 was a current to carry it along or a suitable wind which would drive it two and 

 one half miles an hour, without submerging it, one hundred and twenty-one hours 

 approximately would be necessary for the voyage. Unless more than one hutia 

 was carried on the island, this voyage would have to be performed by a second 

 hutia which would have to reach the island before the death of the first. It is of 

 course, improbable that these events have ever happened. The habits of the 

 Jamaican Capromys are not such as to render it likely that it would ever have 

 attempted so precarious a sea trip and there are no physical conditions in Jamaica 

 which would have forced it to do so. Contrary to Lowe's assertion there are 

 snakes upon the Islands, one of which represents an autocthonous race. Of course 

 the absence of fresh water and other adverse physical features strictly limit the 

 variety of living forms which the islands can support. Pulmonate gastropods ' 

 occur and a variety of insects — so that the fauna is not surprisingly poor but 



' For a notice of the affinities of f lie pxtrcmply interesting species of land shells peculiar to Swan 

 Island, see Clapp, Nautilus, Jan. 1914, 27, No. 9, p. 97-101. 



