608 



ZOOLOGY 



up of a number of short rings bearing minute spines. The eyes 

 are constructed somewhat after the model of the chaetopod eye as 

 described on p. 478. On the surface of the oral papillae are 

 situated the apertures of a pair of glands — the slime glands. 



Each jaw is composed of two 

 curved, falciform, pointed, 

 chitinous plates, the inner 

 toothed on their posterior con- 

 cave edge ; they lie at the sides 

 of the mouth enclosed by a cir- 

 cular lip. The jaws, as well 

 as the oral papilla?, are de- 

 veloped as modified limbs. 



The legs are not jointed, but 

 rows of papillae give them a 

 ringed appearance ; each con- 

 sists of a conical proximal part 

 and a small distal part or foot, 

 the latter terminating in a 

 pair of horny claws. 



The ventral surface is reddish 

 in colour, the dorsal darker : 

 the latter presents an elaborate 

 pattern — which varies greatly 

 in different individuals — pro- 

 duced by minute mottlings of 

 various colours and tints — 

 green, red, and brown, and the 

 arrangement of these in stripes 

 and bands. 



Body - wall and body - 

 cavity. — The wall of the body 

 consists of a cuticle, a layer of 

 deric epithelium with an un- 

 derlying layer of fine fibres, a 

 layer of circularly arranged 

 muscular fibres, and a layer of 

 longitudinal fibres divided into 

 a series of bundles. A layer of 

 epithelium lines the wall of the 

 body-cavity and invests the 

 contained organs. Incomplete muscular partitions divide the cavity 

 into a median and two lateral compartments, in addition to the 

 pericardium, or space in which the heart is lodged ; the lateral com- 

 partments send prolongations into the legs. As in the Arthropoda 

 in general, the body- cavity is a haemoccele, and is filled with blood. 

 The enteric canal (Fig. 481) begins with a small buccal cavity, 



Cr.r y/r/ 



Fio. 4S1. — Dorsal view of the internal organs of 

 Peripatus, cm. anus ; ant. antennas ; brn. 

 brain ; rox. gld. coxal gland of the seven- 

 teenth leg ; $ gen. male genital aperture ; 

 ne. co. nerve-cord ; neph. nephridia ; or. pap. 

 oral papillse ; p/iar. pharynx ; sal. gld. salivary 

 gland ; si. gld. slime-gland ; stoni. stomach. 

 (Combined from Balfour.) 



