1935 ] 
Peripatus in Haiti 
59 
the papillae are subject to some individual variation, but on 
the whole seem to be reasonably constant. Variations in 
the form and attachment of the nephridial tubercles are 
also subject to but slight variation. On the other hand, 
such characters as the dentition of the mandibles and the 
number of leg-bearing segments are subject to sufficient 
variation to render them of lesser importance in the absence 
of other more distinctive characters. Nevertheless it seems 
that the characters used in the table are sufficient to indi- 
cate clearly that the several forms are racially distinct. 
This conclusion is borne out by very striking differences 
in the insect fauna of the several areas which have been 
observed by Dr. Darlington. The three moist mountain 
ranges from which the Peripatus come are separated by 
low, dry, highly xerophytic areas into which such animals 
are utterly unable to penetrate, and it is certain that no 
migration has occurred since such conditions became es- 
tablished. The failure of certain genera of flightless Cara- 
bidse to bridge these gaps is clear evidence that these moun- 
tains are actually isolated after the fashion of true islands. 
In this respect Haiti is quite different from the other West 
Indian Islands on which Peripatus is known to occur since 
it affords clearly isolated mountain ranges. So far none 
have been discovered in Cuba, but two very distinct types 
are known from Jamaica, both inhabiting the extensive 
and continuous Blue Mountain Region in the eastern part 
of the Island. These appear to be very local in occurrence, 
and commonly associated at the same places. One, P. juli- 
formis, var. swainsonse Ckll. is a true Peripatus, but the sec- 
ond which occurs with it is a modified type now relegated to 
the genus Plicatoperipatus. The occurrence of Onychophora 
in Jamaica is, however, so far as known, restricted to the 
Blue Mountains as none have been discovered in other parts 
of the island. 
I have hesitated to propose any new taxonomic names, 
but as the material seems to justify some recognition of the 
five more or less readily distinguishable forms known from 
Haiti, those not already named are regarded as varietal 
forms. In general body color all are essentially similar, 
very dark in life, but after preservation in alcohol showing 
