The Opisthobranchiata of South Africa. 25 



of its free margin. This under pare of the mantle is separated from 

 the foot by a rather deep furrow, and towards the right side cleft 

 by the open longitudinal branchial fissure ; behind the hinder end 

 of the fissure a fine glandular opening. The branchial cavity, m 

 accordance with the form of the shell, rather low ; the curved, 

 brownish gill about 10-12 mm. long by a height of 4-6 and a 

 breadth of 3-5. Over the gill the small, sometimes black punc- 

 tuated, osphradium; above the root of the gill the prominent anus. 

 Below the fore end of the gill the vulva, whose opening is continued 

 in the seminal groove that runs along the low side of the body to 

 the male aperture near the mouth. The broad foot a little narrower 

 before, with a little median notch or slit, on each side of which there 

 is a fine opening ; the sides of the foot through their whole length 

 developed into a strong wing, on the sides filling the space between 

 the two shields, thicker below, rising to a thin convex margin ; the 

 posterior margin free, covering the groove before the under side of 

 the mantle, oblique from the right side to the left and forwards, 

 straight or convex in the middle, with posteriorly prominent edges 

 belonging to the wings of the foot. 



The length of the whitish mouth tube 6-7 mm., its inside 

 yellowish. The whitish bulbus pharyngeals of the usual form, 

 5-6 mm. long. The strong tongue, with deep cleft, with yellowish 

 or brownish yellow rasp, containing 15-20 series of plates, in the 

 sheath 12-16, of which the two hindermost are not fully developed ; 

 the total number of series being thus 27-36. The rhachis not 

 narrow. The plates nearly colourless in their upper half ; their 

 length (in straight line) 1 mm. ; their form was quite as formerly 

 described {I.e., p. 279) ; still, the denticulation was finer than in the 

 specimens from the Atlantic and Mediterranean Sea, and did not 

 seem to extend so far out on the hook as in these specimens 

 (figs. 6-8). 



The salivary glands small but somewhat longer than usual, 

 4-6 mm. long, whitish, applanated (fig. 5). 



The oesophagus short, 3 mm. long. The first stomach 6 mm. long 

 by a diameter of 6-7, its hinder end sunk in the cardia of the second 

 stomach. This masticatory stomach sometimes turned a little to the 

 right, usually lying on the under plate, 2 cm. long by a breadth of 

 1*3 and a height of 1*2. The two lateral masticatory plates 20 mm. 

 long by a breadth of 7*5-8 and a thickness of 2-3 ; the inferior of a 

 length of 16 by a breadth of 9 and a thickness of 3 mm. ; their 

 outside yellowish or chalk-white ; the inside showed the large flat 

 central part white ; this part was inclosed by a broad belt of fine 

 yellow lines, the marginal part white ; the two small holes on the 



