4 THE ANATOMY AND DEVELOPMENT OF PERIPATUS NOVAE-BRTTANNIAE. 



GENERAL CHARACTERS 

 Of the subgenus Paraperipatus. 



1. The females are larger and more numerous and have a greater number of 

 appendages than the males. 



2. There are three spinous pads on the legs ; and the apertures of the enlarged 

 segmental organs corresponding with the fourth and fifth legs, lie in the centre of 

 the proximal pad of these legs. 



3. The outer blade of the jaw is simple, without a small accessory tooth at the 

 base of the main tooth. 



4. The generative aperture is placed immediately behind the last pair of legs. 



5. Receptacula seminis are present in the female, but there are no receptacula 

 ovorum. 



6. The ova are small and without yolk. 



7. Embryos in all stages of development may occur in the uteri of one female. 



DESCRIPTION OF THE SPECIES, PERIPATUS (PARAPERIPATUS) NOVAE- 



BRITANNIAE. 



Colour. The ground-colour of the living animal is black and this is seen, with 

 a lens, to be dotted over with large and small brown or brownish-yellow spots. On 

 the dorsal surface the larger brown spots are arranged segmentally in four rows, 

 namely, one row on each side above the bases of the legs and another row on each 

 side of the median line. The median line is occupied, in preserved specimens, by a 

 prominent narrow black longitudinal tract with segmental intensifications; and in the 

 centre of it is a fine light brownish-tinted or whitish line. The black tract is not 

 so apparent in small specimens, but the median white line is more so. The rest of 

 the black ground-colour developed a bluish tinge after preservation in 5 per cent, 

 formol. To the unaided eye the larger segmental brown spots look like more or less 

 square-shaped areas presenting a block-like appearance, and the intervening space is 

 occupied by the numerous smaller brown spots. The median dorsal white line is 

 continued backwards to the anus where it merges into the brown pigment surrounding 

 the latter. 



On the ventral surface there is a median row of brown spots surrounding the 

 modified segmental epidermal areas known as the ventral organs. The ventral surface 

 generally is less deeply pigmented than the dorsal surface, but the spinous pads of 

 the legs are dark and the pigmentation is also slightly intensified about the segmental 

 grooves at the bases of the legs. 



EXTERNAL FEATURES. 



I. Sexual differences. Of the thirteen specimens in my collection I find three are 

 males. One of these had escaped my notice at the time that the diagnosis of the 



