488 RICHARD EVANS. 



The average length of the specimens belonging to the species 

 Weldoni is 58 mm., and average breadth is 6*25 nun., while 

 the average length of the female specimens of Horsti is 

 only o5'4 mm., and average breadth is 4*G mm.; and of the 

 male specimens the average length is 33*5 mm., and average 

 breadth 3'8 mm. If the eleven specimens of Hoi-sti be 

 taken together, the average length is 34 mm. and average 

 breadth is 4*16 mm. Therefore, in whichever wa}- the com- 

 parison is made, the size of Horsti is to that of Weldoni 

 approximately as three is to four. Another fact brought out 

 by the above measurements is that the females of Horsti are 

 both longer and broader than the males. However, these 

 measui-ements must not be taken as the maximum length 

 and breadth of the species Horsti ; for one female in my 

 collection measures 46 mm. in length and 5"5 mm. in 

 breadth, and one male 40 mm. in length and 4'5 mm. in 

 breadth. 



The last fact mentioned seems to dispose of the specific 

 difference in size, but such is not really the case, for the 

 larger specimen of Weldoni is 65 mm. long and 7'5 mm. 

 broad, and therefore exceeds the largest specimen of Horsti 

 in length by 19 mm., and in breadth by 2 mm. 



The Skin. — The skin is thrown into folds, of which there 

 are about twelve between each successive pair of feet in the 

 middle part of the body. An examination of figs. 10 and 

 13 will serve better than the best possible description to em- 

 phasise the most characteristic difference between the two 

 species here described. When the skin is examined with a 

 hand lens the folds appear continuous across the back, but 

 when looked at through the microscope a narrow, non-pig- 

 mented line is revealed. On these folds are found the papillae 

 which are one of the constant features of the Peripatidae. 

 In the Malay forms, as well as in the Suraatran species, they 

 resemble in structure the papillte of the Neotropical forms. 

 Among the dorsal papillee ai'e found both primary and acces- 

 sory ones, the former consisting of a basal portion which 

 varies in shape between a cylinder and a cone (figs. 7 and 8), 



