MONOGRAPH OP THE GENUS PERIPATUS. 469 



next the external opening. Considering the easy nature of the 

 observations required, Professor Ernst's statements display a 

 very extraordinary method of work. 



Colour. — My observations on this point were made on 

 spirit specimens, and cannot therefore have the value of those 

 of Ernst, who had the living animals before him. He says : 

 " The colour is brownish black, with a diffused black line on the 

 middle of the back ; the ventral side is dark flesh-coloured." 



In all my preserved specimens the colour was brown, 

 darker in some than in others ; in the specimen figured it is 

 as dark as in any in my possession. The ventral surface, 

 moreover, was of the same colour as the dorsal. As these 

 specimens came from Caracas, and have become distinctly 

 paler since I first saw them, it seems pretty clear that the 

 colour of this species is much affected by spirit. It will be 

 remembered the brown pigment of P. capensis was changed 

 by the action of spirit. The same fact has been observed 

 by Grube (see below, p. 480), who found that the pigment was 

 partly dissolved by the spirit, and also by myself in some 

 specimens brought alive from Demerara by Mr. W. L. Sclater 

 (No. 41). 



The Ridges and Papillae of the Skin. — The ridges are 



more clearly marked, and the papillae of the dorsal surface are 

 less numerous. The dorsal white line is not present, so that 

 the ridges are continuous right across the dorsal middle line. 

 Further, there is for the most part only one row of papillae on 

 each ridge, whereas in the South African and New Zealand 

 species there is considerable irregularity in this respect. 

 The fine diagonal lines, which break up the rows of papillae 

 into lozenge-shaped areas, are absent in this species. The 

 ridges extend for the most part right across the dorsal surface, 

 but here and there, particularly at the level of the legs, there 

 are accessory ridges extending across the middle line and 

 stopping short a little distance on each side of it. They cause 

 a slight deflection of the contiguous main ridges (fig. 6). 

 Many of the papillae — particularly those on the legs — are 

 divided by a constriction into two main portions (fig. 12) — 



