350 NOTES ON SOME BRITISH NUDIBRANCHS. 



LOMANOTUS GENEI, VEKANY. 



(Hekgh, Beitr. zur Keniif. AeoJidiadnv, vi. pp. 5-8, and vii. G'2-3. 

 Vayssikke, Mull. Opisth. tie Marseille, part iii. 87-91. (Jamble, Ann. 

 Mag. N. //., scr. 6, vol. ix., 1892, p. 379.) 



One large specimen from riymouth Sound, kindly given me by 

 Mr. W. I. Beaumont. 



The colour of the preserved specimen is yellowish white suffused 

 with brown, which is deepest on the pericardium, rhinophores, oral veil, 

 mantle margin with papilla^ and on the tail. There are no white dots. 

 Some, but not all, of the papilla3 have colourless transparent tips. 



The length is 26 mm., the breadth at most 8, and the height 9, 

 including the raised margin. This margin starts from the rhinophore 

 sheaths and is 2-3 mm. wide. It bears thirty-two papilhe on the right, 

 and thirty on the left side, and is bent into six undulations, three 

 upwards and three downwards. The largest papilhe are those in the 

 centre of these undulations and are about 4 mm. high ; the rest are 

 about half the size. The papilhe (Fig, 6) are distinctly sjjoon-shaped, 

 the convex surface being generally outside, but sometimes inside. At 

 the base of the larger papilla3 are two folds on the inside. The margin 

 is entire round the tail and forms a horizontal fin. The anus is 15 mm. 

 from the anterior end, and the genital orifices G mm., just behind the 

 rhinophores. The oral veil bears four distinct digitations, two on each 

 side, about 2 mm. long. The rhinophore sheaths are about 3 mm. high; 

 the right bears five digitations; the left, tiiough apparently uninjured, 

 has only one. The foot is produced into short pointed angles and 

 grooved. The upper lamina is much stronger and thicker than the 

 lower. 



The jaws are yellow, rather soft and llexible, and much as described 

 by Bergh. The edges for some distance inwards are covered by a 

 mosaic of plates or scales with denticulate edges (Fig. 8.). The 

 masticatory process is very short. 



The radula corresponds in general with the descriptions of Bergh and 

 Vayssiere. It consists of thirty-two rows. The teeth are large, 

 crowded, and yellow at the sides of the rows; smaller, spaced, and 

 colourless in the centre. In this specimen, and in all tiie smaller ones 

 observed, the radula has a great tendency to break and become con- 

 fused, and it seems impossible to spread it out evenly. It is hard to 

 say whether there is a central tooth or not, as the arrangement appears 

 to be not quite symmetrical. Down the rhachis run four to five irregular 

 and not quite straight rows of very irregularly shaped teeth (Fig. 7. a.), 

 bearing a central cusp and three to seven pointed denticles of various 

 sizes on either side. To the right and left of these teeth the rows be- 



