ONYCHOPHORA OR PROTOTRACHEATA. 319 



In its possession of trachea and nephridia this Type zs an 



interesting connecting link ; in many ways it seems to be an 



old-fashioned survivor of an archaic stock. There are about 



half a dozen genera very widely distributed. 



The Onychophora are very beautiful animals. Prof. 



Sedgwick says : " The exquisite sensitiveness and continu- 

 ally changing form of the antennae, the well-rounded plump 



body, the eyes set like small diamonds on the side of the 



head, the delicate feet, and, above all, the 



rich colouring and velvety texture of the 



skin, all combine to give these animals an 



aspect of quite exceptional beauty." They 



are shy and nocturnal, with a great dislike to 



light. They seek out damp places under 



leaves and among rotting wood. They feed 



on insects, which they catch by the ejection 



of slime from the oral papillae. The slime 



is also squirted out when they are irritated. 



To their shy habits their persistence is 



possibly in part due. They are able to 



move quickly, somewhat after the fashion of 



millipedes, especially like Scolopendrella. 



They have been seen to climb up vertical 



glass plates. When at rest or irritated they 



coil up in a circle. 



FIG. 167. Ex- 

 Like some other archaic types, e.g. Dipnoi, the ternal form of 



Onychophora have a very wide range of distribution, Peripatus. 



which may he briefly indicated : Pcripatus (tropi- After Balfour. 



cal America and tropical Africa) ; Eoperipatus (Indo- 



Malay) ; Peripatoides and Ooperipatus (Australasia) ; sf^ieTf . 



Opisthopatus (Chili and South Africa) ; Paraperipatus 



(New Britain); Peripatopsis (Central Africa). 



A more Detailed Account of Peripatus 



Form. The body suggests an Annelid or a caterpillar, but, apart 

 from the appendages, there is no external segmentation. There is a 

 clear dorso-median line. Over the soft skin are numerous minute warts 

 with small bristles. The mouth is ventral and anterior ; the anus 

 terminal and posterior. 



Appendages. The first are the large, ringed antennae ; then follow 

 the sickle-like jaws in the mouth cavity; a little farther back are two 

 oral papillae from which slime is exuded. Then there are the 14-42 

 stump-like legs, each with two terminal chitinous claws. 



