The Opisthohranchiata of South Africa. 9 



5. Apl. eusiphonata, B. ii. sp. 

 PI. III., figs. 5-15. 



Of this form one specimen was procured in May, 1902, at East 

 London. 



It had a length of 8-5 cm. by a height of 5 and a breadth of 4-5 ; 

 the height of the rhinophores and tentacles was 5 mm., the length 

 of the foot- wings was 6-5, their height (on the inside) 2 cm. ; the 

 length of the mantle 3-3 cm., the breadth 24 ; the height of the large 

 sipho 2-2 cm., its breadth at the base 2-6, at the upper end 1-2 cm. ; 

 the breadth of the foot 2 cm. — The ground colour of the upper side, 

 whitish, the head and the neck blackish, due to black partly con- 

 fluent stripes ; the outside and inside of the foot- wings with spread 

 rather large irregular black spots ; the mantle clear grayish with 

 a few black spots and some black stripes radiating from the centre ; 

 the foot clear dirty yellowish. 



The form as usual. The foot-wings large, reaching to the root 

 of the very short tail, their margin very slightly undulated, the 

 outside and the inside quite smooth. The mantle of oval circuit, 

 the anterior end a little more pointed, on the centre of the somewhat 

 convex upper side there may be a fine opening; the sipho (figs. 5, 6) 

 very large, embracing a great part of the upper side, fixed to the 

 hinder wall ; the anus was seen in the upper part of the siphonal 

 channel ; the large mantle quite covered the gill with exception 

 of its pointed end (fig. 6). In the mantle no trace of a slicll could 

 he found. The somewhat brownish gill strongly curved, the chorda 

 measured 14 mm., its height 11, its thickness 6 mm., on the 

 underside a broad furrow between the lamellse ; its last fourth freely 

 projecting. 



The central nervous system as in other true Aplysiae ; the pleural 

 ganglia not half as large as the pedal, lying next to these and 

 before them. 



The length of the mouth tube 5 mm. The bulbus pharyngeus 

 10 mm. long by a height and a breadth of 8. The hooks of the gray 

 palate as usual, somewhat grayish, as much as 0*20 mm. high (fig. 8). 

 The mandibular plates strong, brown, broader in the upper end, 

 4 mm. high by a breadth of 2-5 and a thickness of 0-25 mm. ; their 

 high elements (fig. 7) of a diameter of 0-009 mm. The tongue with 

 brown rasp, containing 28 rows of plates, in the sheath 18, 

 the total number of rows being thus 46 ; the number of lateral 

 plates on each side of the median about 26. The plates were 

 yellow, only the outer nearly colourless ; the breadth of the median 

 0-25 mm.; the length of the body of the first lateral 0"25, the length 



