42 THE ANATOMY AND DEVELOPMENT OF PERIPATUS NOVAE-BRITANNIAE. 



EXPLANATION OF THE PLATES. 



PLATE I. 



Fig. 1 . Adult female from dorsal aspect, x 2. 



Fig. 2. Sketch of male, x 4. 



Fig. 3. Enlarged view of portion of the back of the animal to show the interruption 

 of the papilliferous ridges in the middle line ; also the single row of papillae on each ridge. 

 [In the Neotropical species the ridges usually carry a single row of papillae but they are 

 not interrupted in the middle line. In the Cape and Australian species there is a median 

 interruption but the papillae occur irregularly and in several rows (Sedgwick). The two 

 species P. tholloni and P. tuberculatus recently described by Bouvier seem to be intermediate 

 in this respect.] 



Fig. 4. Enlarged view of portion of the ventral surface. The papillae of the ventral 

 surface differ from those on the dorsal surface in that they occur more irregularly, often 

 in more than one row on the ridges. Among the more numerous smaller papillae are 

 numbers of much larger papillae placed with considerable regularity in transverse rows and 

 having a tubercular appearance when viewed with a lens. Similar tuberculiform papillae 

 have been described by Bouvier on the dorsal surface of P. tuberculatus. The ventral organs 

 are rendered prominent by their brown pigment. 



Fig. 5. Anterior end in ^-ventral view, showing the characters of the jaws, the lips 

 and the oral papillae. The modified appendages which carry the jaws are well shown and 

 the fact that the jaws are homodynamous with the claws of the ambulatory appendages is 

 well illustrated. The figure also shows the dorsal fleshy protuberance known as the "tongue" 

 with its median row of chitinous denticles. Only the basal portions of the antennae are 

 indicated. The oral papillae are characteristically flat-topped as if a slice had been cut off. 



Figs. 6 a and 6 6. Free ends of the antennae of individuals of different ages to show 

 intercalation of new rings between the older rings during the free life of the animal. 

 Fig. 6 a relates to a specimen 14-75 mm. in length, while Fig. 6 6 relates to one 54-75 mm 

 long. The former had 33 rings in each antenna and the latter about 50. 



Fig. 7. Ventral view of an ambulatory appendage of the 4th or 5th pair. The external 

 opening of the enlarged segmental organ is seen to occupy the centre of a prominent tuber- 

 culiform structure which lies in the centre of the third spinous pad and causes an interruption 

 in the continuity of the latter. The absence of primary papillae at the base of the "foot," 

 i.e. at the insertion of the "pes" on to the "crus," is to be noted. In P. capemis there 

 occurs a pair of primary papillae, the basal papillae, in that position. 



Figs. 8 a and 8 b. Dorsal views of feet to show variation in the relative positions of 

 the primary papillae. In Fig. 8 a the dorsal papilla lies near the anterior papilla. In 

 Fig. 8 b the dorsal papilla is median. 



Figs. 9 a and 9 6. Views of the posterior extremity of a female from the ventral and 

 lateral aspects. The generative orifice with its tumid lips lies posterior to the last pair of 

 legs. The anus is quite terminal. 



