ON THE NUDlBRANCHfATA. 13 



Breadth, including 

 Le "8 tlu Cerata. 



mm. mm. 



(2) 108-5 33-5 



(3) 50 33 This specimen is exceptionally 



broad. 



(4) 59 19 Long and slender. 



(5) 43-5 20 



(6) broken in two, 



but about 54, 19 



All the specimens except the last were captured at Station 325, Scotia Bay, South 

 Orkneys, in 9-10 fathoms. In two cases it is recorded that the temperature was 29 

 Fahr. The last specimen was found in a shore pool, Scotia Bay, South Orkneys; 

 temperature, 30 Fahr. It is much damaged, nearly all the cerata being broken 

 though not detached, but it probably belongs to the same species as the others, the 

 anatomy being identical. 



The body, rhinophores, and tentacles are of a dirty white ; the cerata are of a faded 

 pink, but this tint is stronger in the large specimens than in the smaller ones. The skin 

 appears to be naturally smooth, but in some specimens is covered with wrinkles and 

 blisters, apparently caused by the preserving fluid. When the integuments are held 

 up to the light (but not otherwise), a network formed by intersecting bundles of fibres 

 can be seen within the skin. This pattern is much more developed in some specimens 

 than in others. 



The largest specimen is 122 '5 mm. long, 35 high, and 39 across the broadest part 

 of the back, including the cerata. The shape and proportions of the body somewhat 

 recall Tritonia, but the external characters are those of an seolid. The foot is broad, 

 with expanded margins, and measures 30 mm. at its widest part. It is rounded and 

 grooved in front, with no trace of tentacular prolongations at the sides. 



There is no trace of a frontal veil, but the oral tentacles which rise on each side 

 of the mouth are unusually large and stout, being about 20 mm. long and 6 wide at 

 the base. They are curved upwards and inwards, so as to present the appearance of a 

 crescent when seen from the front. Between them is a slight prominence. The rhino- 

 phores are about 6 mm. behind the oral tentacles and close to one another, the interval 

 between them being only 4 '5 mm. They are 10 mm. high, and bear respectively 

 fifteen and seventeen rings, most of which run completely round the stalk, though the 

 last few are less regular, and interrupted here and there. 



The cerata amount to about 800 on each side, that is, 1600 in all. They are set 

 upon the dorsal margin, which is sinuous as in Lomanotus, with five undulations 

 outwards and as many inwards. They begin slightly before the rhinophores, but on 

 the lateral, not the anterior margin of the body, and are continued until its posterior 

 termination, the tail projecting only 5 mm. They are of varying size, the tallest being 

 about 18 mm. high, 4 mm. broad at the base, and two at the tip. The colour is faded 

 pink. The largest are inside ; the smallest, which are mere tubercles, less than 1 mm. 



(ROY. soc. EDIN. TRANS., vol.. XLI., 521.) 



