The Opistliohranchiata of SontJi Africa. 107 



transparent sphere, flattened on the under side. The length was 

 6-8 cm. by a breadth of 5-5 and a height of 4 ; the submedian 

 (inspiratory) cleft 1 cm. long ; the breadth of the mantle brim, that 

 was bent downwards and touching the margin of the foot, 13 mm. ; 

 the aperture of the gill cavity 9 mm. broad ; the length of the ten- 

 tacles 8 mm., that of the penis 2-6 cm. by a diameter of 0-5 ; the 

 length of the foot 4 cm. l)y a breadth of 2-2 ; the length of the tail 

 12 mm. — The upper side of the mantle uniformly coloured greenish 

 white, the under side of the mantle (except the broad inspiratory 

 furrow), the neck, and the upper side of the foot velvet black; the 

 tentacles, the penis, and the sole of the foot white ; the intestines 

 did not shine through. 



The mantle was even all over ; its under side densely transversely 

 striated, no distinct expiratory furrow. The ophthalmophoria very 

 small, and eyes not visible. The penis strong, nearly cylindrical. 

 The foot as usual. 



The shell 3 cm. long by a breadth of 2, as in the Mars, leiotolemma 

 quite thin, membranous, slightly yellowish, easily loosened from the 

 intestines, and when spread in water assuming the ordinary form of 

 the Marsenia shell (fig. 1). 



The situation of the intestines quite as usual. The olfactory organ 

 (Spengel) 15 mm. long by a breadth of 9, dirty brown with whitish 

 rhachis ; the curved gill whitish, about 2*5 cm. long, its very thin 

 and narrow leaves up to 8 mm. high. The ventricle of the heart 

 5 mm. long ; the kidney and the foliated gland exhibited the usual 

 relations and structure. 



The bulbus pharyngeus of usual form, but small, 6 mm. long by a 

 breadth of 6 and a height of 3-5, whitish. I did not succeed in 

 determining the form of the mandibular plates. The tongue as 

 usual ; in the faintly yellowish rasp 22 series of plates, in the sheath 

 (that was bent directly forwards and median, reaching to the anterior 

 of the bulbus) 46, the total number of the series thus being 68. The 

 median plates quite colourless, the breadth between their legs 0*22 mm. 

 The median plates narrower in front, with 4-6 sharp denticles on each 

 side of the pointed hook (fig. 18) ; the lateral plates of the common 

 form on one margin unusually finely denticulated, on the other with 

 4-6 more clumsy (fig. 2) denticles. The end of the rasp-sheath 

 smaller than usual (fig. 19). 



The oesophagus as usual and with a widening. On the anterior 

 side of the ■psaltermm (the foliated or glandular stomach) the trans- 

 versely situated second stomach or crop. The psalterium itself 

 semiglobular, somewhat of a cup-like shape, of a transverse diameter 

 of 9 mm., yellowish. The proper (third) stomach as usual. The 



