PERIPATUS GUIANENSIS. 149 



External Chaeacters. 



The Dimensions of the Living Animal. — The greatest 

 length the male specimen seemed to be capable of, even when 

 in motion, was about 35 mm. The female specimens seem to 

 consist of individuals of all ages, ranging from a young one 

 containing no embryos, and measuring about 30 mm. in 

 length when in motion, to older ones full of young in differ- 

 ent stages of development, and measuring", when fully ex- 

 tended, no less than 80 mm. in length. In proportion to their 

 length they seem to be stouter than P. im-Thurmi. Their 

 girth, however, depends to a considerable extent on the state 

 of development attained by the young which they contain. 

 In the moving animal the legs are slender, and situated at a 

 considerable distance from one another, but on contraction of 

 the animal, either when irritated or at death, both the body 

 and the appendages shorten and become thicker, and the 

 spaces between the successive pairs of legs almost disappear 

 in spite of the fact that in the living animal the width of the 

 spaces in question is to that of the leg as seven is to five. 

 This latter fact demonstrates in the most clear way the utter 

 futility of giving the dimensions of dead specimens, which 

 are invariably more or less contracted. 



The Colour of the Living Animal. — The colour varies 

 considerably in tint ; nevertheless the pattern is maintained. 

 On the dorsal aspect the colour is some shade or other of 

 brown, and on the ventral of grey. The variation occurring 

 in different individuals is brought about by the presence or 

 absence of a pinkish constituent, which gives the animals' 

 colour a warmer or colder tone. The mid-dorsal position is 

 occupied by a chocolate-coloured line of a decidedly dark 

 tint, with lozenge-shaped areas roughly corresponding to the 

 appendages arranged on it. Smaller areas of a similar shape 

 may be intercalated so as, to some extent, to interfere with 

 the apparently segmental arrangement of the bigger ones. 

 On either side of the line in question is found a zigzag one 



