ONYCHOPHORA OR PROTOTRACHEATA. 



303 



In its possession of trachea and mphridia this type is 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 species of Peripatus are very beautiful animals. Mr. 

 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. 145. Ex- 

 ternal form of 

 Peripatus. 

 After Balfour. 



Note antenna? and 

 simple legs. 



Like some other archaic types, e.g. Dipnoi, the 

 Onychophora have a very wide range of distribu- 

 tion, which may be briefly indicated : Peripatus 

 (tropical America and tropical Africa) ; Eoperipatits 

 ( Indo- Malay ); Peripatoides and Ooperipatus (Australasia) ; 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 



