

342 N0TE8 ON SOME BRITISH NUDIBRANCHS. 



The buccal parts have been extracted. 



No further examination was made in order not to injure the unique 

 specimen. 



I have also examined five specimens seen alive at Plymouth in April, 

 1905. They vary somewhat in external appearance, and may be 

 described separately. 



A. One specimen, rather variable in shape, but flattish. When fully 

 stretched out and moving its length is 60 mm. and its breadth 32. It 

 is active in its motions. The main colour of the back is mottled pur- 

 plish brown of various shades, the deepest of which is almost black. 

 The general colour is lighter towards the margin, though here the 

 darker shades are more conspicuous by contrast. There are a few 

 irregular sandy-grey markings here and there, especially in front of the 

 rhinophores.and twelve sandy-yellow star-like figures arranged symmetri- 

 cally in four lines between the rhinophores and the branchial pocket. 

 The back is covered with fiat tubercles, very slightly prominent, and 

 more or less of the same size (not more than 1 mm. in breadth), except 

 those forming the centre of the stars, which are about twice as large as 

 the others. The tubercles forming the stars appear to be set in a stel- 

 late figure, but the pattern is due to pigment rather than to the arrange- 

 ment of the tubercles. The edge of the rhinophore pockets is set with 

 small tubercles. The rhinophores are elongate, with about fifteen per- 

 foliations. They are olive coloured, and the stalk is long compared 

 with the laminated part. The braucliial pocket is slightly raised and 

 tuberculate. The branchiaj are six, tripinnate, sandy yellow, with pur- 

 plish fiecks. The anal papilla is purplish, but the edge is crenulate 

 and distinctly margined with sandy yellow. The foot is grooved in 

 front and the upper lamina notched. The tentacles are cylindrical and 

 elongate, which makes the whole head look unlike that of A. tubcrcidata. 

 The under side is white, but in this and in all the specimens there are 

 a few purplish spots on the under side of the mantle, which is rather 

 ample and overhangs the foot all round. 



B. In a second specimen of about the same size the characters are 

 exactly the same, but there are only four stellate figures on each side, 

 and tliey are less regular both in their formation and their arrange- 

 ment. The pockets of the rhinophores and the branchiae are very 

 distinctly crenulate and tuberculate. 



C. Three similar but rather smaller specimens are paler in colour, 

 and the stellate figures are only imperfectly developed. The branchiae 

 are as many as seven or eight. 



The internal characters of all the specimens are much the same. 

 The blood gland is large, double, purple or greyish. The central 

 nervous system is not quite as in A. tahcrciUata. Seen from the upper 



