TWO NEW SPECIES OF ONYCHOPHOEA. 487 



avoid repetition the two species will be described togetliev 

 as far as possible, and the features in which they differ will 

 be pointed out as they arise, 



B. External Characters. 



Colour. — The colour of the two species here described is 

 slightly different, especially on the ventral surface. The 

 dorsal surface of the species Weldoni is coloured dark 

 brown, while that of the species Horsti is lighter; that is, 

 it is warmer in tone, as if there were a certain amount of 

 pink mixed with the brown. The mid-dorsal position in 

 both species is occupied by a very dark chocolate-coloured 

 line, of a much deeper hue than the neighbouriug parts. It 

 extends uninterruptedly from close to the anterior end 

 almost to the terminal anus. The appearance of a dark line 

 is brought about by the greater development of pigment in 

 the papillee situated on either side of a completely uou-pig- 

 mented but exceedingly narrow line which occupies the 

 median position. The dorsal surface, especially in the species 

 Weldoni, has pale spots, distributed with a certain amount of 

 regularity all over it. This appearance results, on the one hand, 

 from broken primary' papilhe, and, on the other hand, from 

 the primary papillae containing less pigment than the others, 

 and consequently presenting a yellowish-white appearance. 



The ventral surface in the species weldoni is coloured 

 yellowish-gi*ey with small spots of brown. In the species 

 Horsti it may be almost as in Weldoni, or it may have a 

 decidedly pink appearance, which in some cases may even 

 push between the legs towards the dorsal surface. In both 

 species there is a row of whitish areas, segmentally arranged 

 along the mid-ventral line between the legs of each pair. 

 They correspond to, and lie below, the ventral organs, which 

 in the genus Eoperipatus do not completely degenei-ate in 

 the adult condition. 



Dimensions. — The two species here described differ con- 

 siderably in size, Weldoni being much larger than Horstj. 



