190 
ORIGIN OF LIFE IN AMERICA 
fauna. This is a point, of considerable interest and import¬ 
ance, and requires to be more closely studied in a recon¬ 
sideration of the true relationship of the members of other 
groups of invertebrates. 
This relationship is clearly recognisable among the ter¬ 
restrial Isopods or wood-lice, which have been described, 
by Miss Richardson. Tylos lat.reilli, as already quoted, 
is a typical Mediterranean species, which has been dis¬ 
covered in southern Florida, where also another species, 
Tylos niveus, occurs. Both of these are now recorded from 
Bermuda. The European genus Porcellio is represented by 
two species, one of them (Porcellio parviciornis) new to 
science. Metoponorthus sexfasciatus, a typically Mediter¬ 
ranean species, also found in the Canaries and Azores, occurs 
in Bermuda, but nowhere else in America. Another species 
peculiar to Bermuda (Philoscia bermudensis) is closely 
related to the west European Philoscia couchi. The 
American affinities are likewise surprisingly interesting. 
Uropodias seems to be related to the West Indian genera 
Haplarmadillo and Sphaeroniscus, and this strikingly distinct 
genus is quite confined to Bermuda with the one species, Uro¬ 
podias bermudensis. The truly archaic Actoniscus ellipticus, 
which is only known from Bermuda and from the coast of the 
mainland near New Haven and Long Island Sound, is one 
of the only two members of the family Trichoniscidae. Its 
distribution is suggestive of a former land connection towards 
north-eastern North America. The other Actoniscus is con¬ 
fined to California. Finally, Leptotrichus granulatus, also 
peculiar to Bermuda, may be mentioned as the only occurrence 
of a very ancient Old World genus in America.* 
The only native spider which, according to Dr. Verrill,f was 
mentioned by the early writers, was the great silk spider 
(Nephila clavipes). The enormous webs which this spider 
constructs between trees at a distance of fifty feet from one 
to another excited their admiration, and suggested to them 
that the threads might be used in the manufacture of silk 
tissues. This has actually been done in Brazil, I believe, 
* Richardson, Harriet, “Isopods of Bermuda.” 
t Verrill, A. E., “Bermuda Islands,” XI., p. 829. 
