OF PERIPATUS CAPENSIS. 897 



[Moseley (Phil. Trans., 1874, PI. 73, fig. i) states that the 

 tracheae branch, but only exceptionally.] 



Situation of the tracheal apertures. Moseley states (No. 13) 

 that the tracheae arise from the skin all over the surface of the 

 body, but are especially developed in certain regions. He finds 

 "a row of minute oval openings on the ventral surface of the 

 body," the openings being "situate with tolerable regularity in 

 the centres of the interspaces between the pairs of members, but 

 additional ones occurring at irregular intervals. Other similar 

 openings occur in depressions on the inner side of the conical 

 foot protuberance." It is difficult in preserved specimens to 

 make out the exact distributions of the tracheal apertures, but I 

 have been able to make out certain points about them. 



There is a double row of apertures on each side of the 

 median dorsal line, forming two sub-dorsal rows of apertures. 

 The apertures are considerably more numerous than the legs. 

 There is also a double row of openings, again more numerous 

 than the legs, on each side of the median ventral line between 

 the insertions of the legs. Moseley speaks of a median row in 

 this position. I think this must be a mistake. 



Posteriorly the two inner rows approach very close to each 

 other in the median ventral line, but I have never seen them 

 in my section opening quite in the middle line. Both the dorsal 

 and ventral rows are very irregular. 



I have not found openings on the ventral or dorsal side of 

 the feet but there are openings at the anterior and posterior 

 aspects of the feet. There are, moreover, a considerable num- 

 ber of openings around the base of the feet. 



The dorsal rows of tracheal apertures are continued into 

 the head and give rise in this situation to enormous bundles of 

 tracheae. 



In front of the mouth there is a very large median ventral 

 tracheal pit, which gives off tracheae to the ventral part of the 

 nervous system, and still more in front a large number of such 

 pits close together. The tracheae to the central nervous system 

 in many instances enter the nervous system bound up in the 

 same sheath as the nerves. 



