The Opisthobranchiata of South Africa. 13 



two series of (about 10) short cones. The masticatory stomach 4 mm. 

 long by a diameter of 5 ; its armature as usual, but the pyramids 

 were nearly all gone ; these were of the usual form, clear yellowish, 

 transparent. The third stomach 5 mm. long by a breadth of 3*5 ; 

 at its cardiac end distinct round impressions left by cones, which 

 were absent. 



The grayish brown liver irregularly globular, its greatest diameter 

 being 10 mm. ; the gall-bladder whitish. 



The white hermaphrodite gland 4 mm. broad by a height of 3 

 and a thickness of 2, somewhat meniscus formed ; in its lobules 

 ripe genital elements (zoosperms). The penis whitish, grayish in 

 front. The conical white glans 1*5 mm. long. 



This form seems allied to the Apl. Sibogse (I.e., 1905, p. 9, 

 taf. vi., figs. 36-42 ; taf. vii., figs. 1-6). 



8. Apl. monochroa, B. n. sp. 

 PI. I., figs. 22-24; PI. II., figs. 2-7. 



Three specimens were procured at Hermanus on January 15, 1897. 

 Two individuals were dissected. 



They were of about the same size, and otherwise resembled each 

 other, were uniformly white, except that the inside of the rhinophores 

 and tentacles was blackish brown. 



The largest one was 4 '5 cm. long by a breadth of 2 and a 

 height of 2-5 ; the foot-wings reaching to the head, 2-5 cm. long by 

 a height (on the inside) of 1 ; the length of the oval mantle-hole 

 7*5 mm. (fig. 22), the white foot 10 mm. broad. 



The form was as usual ; the whole of the back quite even. The 

 shell rather variable in form, thin, in one specimen quite cuticular, 

 in another merely in the two posterior thirds slightly calcified, 18 mm. 

 long by a breadth of 16, rather depressed (fig. 2). Near the 

 hinder end of the mantle-hole, a little to the right, the mantle sends 

 out a sort of siphonal (expiratory) fold separated from the free 

 mantle margin protecting the gill (fig. 22). The curved whitish gill 

 13 mm. long by a height up to 8 and a breadth to 4*5 mm., the 

 rhachis rather strong, on each side about 18 tufts of lamellae ; 

 the gill projecting freely by about a third. The foot rather narrow, 

 somewhat broader in front. 



The mouth tube 4 mm. long. The whitish bulbus pharyngeus 

 6*5-7 mm. long by a breadth and a height of 6; the yellowish 

 mandible-plates not broad, their thin elements of a height up to 

 - 12 mm. by a diameter of 0*007 (fig. 23). The palate in the middle 

 with the usual network with glands ; the palatal plates weak, with 



