The Opisthohranchiata of South Africa. IT 



The very retracted and contracted mouth tube about 7 mm. long. 

 The plump hulhus j^harjpigeus 15 mm. long and high by a breadth 

 of 12, of usual form, with the end of the rasp-sheath somewhat 

 prominent on the lower side posteriorly ; the strong inferior retractor 

 muscles of the bulbus issuing from the region of the margin of the 

 hinder disk of the body. The strong, somewhat brittle mandible 

 plates of a length of 7 mm. by a breadth of 3*8 and a thickness of 

 0"4 mm. ; they were yellowish brown on the free side, on the breach 

 yellowish white ; their closely set angularly cylindrical elements of 

 a diameter of 0-016 mm. (tig. 19). On each side of the ^mlate a thin, 

 dirty yellowish plate, 3 mm. broad, densely set with (fig. 18) horny, 

 compressed hooks, of form as in other Aplysiidge, of a length up to 

 0*8 mm. by a breadth to O'lO. This spinous covering continued a 

 little behind the roof of the pharynx. The large tongue with deep 

 cleft ; the rasp brownish yellow, containing 42 se ies of plates 

 (counted at the margin of the rasp), in the sheath 44, of which 

 the 5 hindermost are not fully developed ; the total number of 

 series about 86 ; the 6 foremost on the tongue very incomplete and 

 partly damaged. The number of plates in the series seemed to be 

 about 200. The plates were yellow; the length of the median was 

 about 020 by a breadth up to 0-07 mm. ; the height of the two 

 outermost lateral plates was about 0'14-0"16 mm. ; through the 

 series the height of these plates rose to 0'37 mm. The median 

 plates in form very different from those of the proper Aplysiae, 

 longish, narrower in front, with a small denticulated hook at 

 the anterior end (figs. 14, 15); the lateral plates of ordinary hook 

 form (figs. 16-17). 



The yellowish white salivary glands long, reaching to the cardia, 

 nearly cylindrical, of a diameter of 2 mm., thinner behind; the 

 efferent duct quite short. 



The length of the gray oesophagus with its dilatation (proven- 

 triculus) 4 cm. by a diameter of 7-12 mm., its interior with fine 

 longitudinal folds and plump villi. The (masticatory) stomach 

 brownish gray, somewhat roundish, of a (transverse) diameter of 

 2*5 cm. by a length and height of 1*7 ; the usual nerves run along 

 this stomach, anastomosing at the pylorus and forming a circle around 

 this, and then continued on the second stomach. The anterior part 

 of this stomach had 8 somewhat depressed angular-roundish facets 

 belonging to the stomach plates, and behind them 2-3 series of 

 smaller and less regularly set facets. The 8 large very hard 

 stomach plates were irregularly pyramidal ; the broad basis convex, 

 very smooth ; the height and the breadth nearly the same, 7-9 mm. ; 

 the base and the top brown ; otherwise the base was chalk-white. 



2 



