114 



THE PUR SEALS OP THE PRIBILOF ISLANDS. 



ventral views (figs. 12, 13), however, show that the outline of the dorsal lip is some- 

 what different from that of the ventral lips. The dorsal lip has a large base 0.27"™ 

 broad by 0.128">" long, which bears the usual pair of sense papillae, one on each 

 anterolateral margin; it bears also an anterior double-lobed projection 0.144'°" broad 

 by 80 f.1 long, the measurements varying somewhat in diiierent specimens; a dentig- 

 erous ri^ge is present on the inner surface of the anterior projection; the ventro- 

 lateral'lips are essentially of the same diflerentiation, namely, a large base with a 

 smaller double-lobed anterior projection, but in the ventral lips the base is longer, 

 and the anterior projection extends more Into the space between the three lips, so that 



Fig. 12. 



the lobes are somewhat concealed; on apex view (flg. 14) and on transverse section 

 (fig. 15), however, these lobes are plainly visible; they are provided with an inner 

 dentigerous ridge; the basal portion of each ventral lip is provided with the usual 

 sense papilla. The excretory pore (figs. 11, 14) opens in the median line between 

 the ventral lips, immediately ventral to the apex of the oesophageal triangle. 



Cervical alae are absent; cervical papillae are plainly visible about 1""" from the 

 anterior extremity. 



The cuticle of the body is provided with 40 to 48 p. transverse bands, which are 

 provided with a much finer striatiou. 



