322 Mr. F. O. P. Cambridge on 
the breaking-up of the genera and species in question into two 
or more. But what precise extension is given to the terms 
genera and species is purely a matter of taste; the actual 
facts are in no way affected. Further, whether we have to 
do with actual or assumed continuity in time and space, 
the warrant for the conception of species disappears: for 
historical-geographical considerations it is too contradictory ; 
the ideas of species as something separating, and of develop- 
ment in time and space, are incommensurable. Thirdly, for 
the purpose of our present study it does not matter at all 
whether the representatives are regarded as identical species, 
or as different forms of the same species, or as nearly related 
species. The point is in the evidence of close relationship, 
and it does not matter much what systematic expression we 
give to this fact. 
CONCLUSION. 
We have now reached the end of our study. We have seen 
that the faunas of higher latitudes represent the coeval relics 
of the almost uniformly developed and almost universally 
distributed Early Tertiary faunas, as they have been evolved 
under the influence of the cooling of the climate, by a process of 
separating out and selection. The similarity of the operating 
causes secured that the same components of the old fauna 
remained behind in both north and south; and thus has 
arisen the great and still well-marked similarity of the two 
faunas. 
XLI.—On a Collection of Spiders from the Bahama Islands 
made by J. L. Bonhote, Esq. ; with Characters of a new 
Genus and Species of Mygalomorphe. By F.O. PicKARD 
CAMBRIDGE, B.A. 
[Plate VIL] 
A SMALL but valuable collection of Arachnida was made in 
the neighbourhood of Nassau by Mr. Bonhote and presented 
to the British Museum. Amongst other interesting forms 
were two adult males of the family Theraphoside, large hairy 
spiders locally termed Tarantulas. For these a new genus 
has been made, and the species is also new: it is characterized 
by the presence of stridulating-spines on the trochanters of 
the first pair of legs and the palpus. 
