566 



CLASS II. ONYCHOPHORA. 



External sexual differences (p. 576) are sometimes afforded 

 by the shape of the genital opening and sometimes by the open- 

 ings of the accessory glands of the male. In many species the 

 apertures of the crural glands, or of some of them, are placed on 

 enlarged white papillae. This occurs on the last leg of the male 



in the Cape species (Fig. 

 336), in some of the Aus- 

 tralasian and in most neo- 

 tropical species. 



Habits.* In their natural 

 haunts they form exceed- 

 ingly beautiful and surpris- 

 ing objects. They live be- 

 neath the bark of rotten 

 stumps of trees, in the 

 crevices of rock, and be- 

 neath stones. They require 

 a moist atmosphere, and 

 are exceedingly susceptible 

 to drought. They avoid 

 light, and are therefore 

 rarely seen. They move 

 with great deliberation, 

 picking their course by 

 means of their antennae 

 and eyes. It is by the 

 former that they acquire a 

 knowledge of the ground 

 over which they are travel- 

 ling, and by the latter 

 that they avoid the light. 

 The antennae are extra- 

 ordinarily sensitive, and 

 so delicate, indeed, that 



they seem to be able to perceive the nature of objects without 

 actual contact. When irritated they eject with considerable 

 force the contents of their slime reservoirs from the oral papillae. 

 The force is supplied by the sudden contraction of the muscular 

 body wall. They can squirt the slime to the distance of almost 

 * Thos. Steel, Proc. Lin. Soc. New S. Wales, 1896, p. 94. 



FIG. 343 bis. Female generative organs of Peri- 

 patus trinidadensis (after Gaffron). 1 Funi- 

 culus ; 2 ovary : 3 duct or funnel of recepta- 

 culum ovorura, the latter not being shown ; 

 4 receptaculum seminis ; 5 anterior end of 

 uterus. 



