2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



found— by Mr. H. H. Smith in 1894 — though many naturalists, my- 

 self among the number, have searched for them. 



It is of course impossible to approach a discussion of the distribu- 

 tion of the onychophores in the same way in which one would ap- 

 proach a discussion of the distribution of better known types, for the 

 number of genera and species yet remaining to be discovered is un- 

 doubtedly large in proportion to the number of the genera and species 

 which have already been described, while we do not know with any 

 degree of accuracy the range of even a single form. 



.In many of the zoogeographically most important regions of the 

 world no onychophores have as yet been found, though in some of 

 them they certainly exist. Unidentified species, which were not pre- 

 served, have been met with in the Philippines and in Fiji, but none 

 have been reported from New Caledonia, Samoa, the Solomon 

 Islands, Halmahera, Celebes, Borneo, the Sunda Islands east of 

 Sumatra, or Madagascar, where almost certainly they occur, or in 

 southeastern Asia outside of the Malay Peninsula, though there 

 should be representatives of the group in Ceylon and southern India 

 as well as in Burma and Siam and the adjacent lands. Excepting for 

 those in the Cape Colony and Natal we know practically nothing of 

 the African types. 



A discussion of the distribution of the onychophores therefore must 

 take the form of a simple exposition of the generally accepted facts 

 in zoogeography and palseogeography, and an exposition of the 

 evidence for or against these facts presented by the species of the 

 group as we know them now. 



THE ONYCHOPHORES APPARENTLY AN ANCIENT TYPE 



Although we have no palseontological evidence upon which to base 

 our statement, it would appear that the onychophores represent a 

 very ancient type for, like most ancient types, (1) they are strictly 

 nocturnal, (2) they are all built upon the same plan with very little 

 deviation from the mean, and (3) they indicate land connections 

 which we know to have been very ancient. 



THE PHYSICAL AND ECOLOGICAL DISTRIBUTION OF THE 

 ONYCHOPHORES 



So far as we know, the onychophores are confined within a re- 

 latively narrow and circumscribed physical range; that is, they re- 

 quire a fairly uniform temperature within very moderate extremes, 

 and a uniformly high humidity. 



