18 NUDIBRANCHIATA. 



and marked with about 30 raised white lines or stripes, which 

 are irreguLarly nodulous and alternately larg-er ; at the sides 

 they are broken up into small tubercles and crowded : tenta- 

 cles and ffilh yellowish : foot whitish, with the sole of a paler 

 hue than the rest of the body. L. 1. B. 0-4. 



Habitat : My friend the late Mr. Barlee dredged on 

 the coast of Shetland a single specimen, w^hich I ex- 

 hibited at the Birmingham Meeting of the British 

 Association in 1849. The Rev. R. C. Abbes procured 

 another specimen from a fishing-boat at Whitburn, co. 

 Dui'ham. South-western coasts of Sweden (Loven and 

 Lilljeborg); Christianiafiord (Asbjornsen) ; Hornbaek 

 in Zealand (Horring, fide Bergh) ; depths 7-40 f. 



Diphyllidia undulata of Meckel (D. Uneata, Otto), to 

 which these specimens were at first considered to belong, 

 is not uncommon in the Mediterranean. It differs 

 from the present species in being of a larger size and 

 proportionally very much broader, as well as in its 

 colour, which varies from whitish to the darkest black ; 

 and the stripes in that species are more numerous, 

 nearly regular, and equal in size. Bergh has also 

 pointed out a distinction as regards the masticatory 

 apparatus. 



Order V. NUDIBRANCHIA TA, Cuvier. 



Body slug-like, soft : 7nantle very large, covering the back 

 and sides : tentacles consisting of one pair or two, which are 

 placed on the front portion of the mantle : eyes sessile, im- 

 bedded in the skin behind the tentacles, at their base ; they 

 are conspicuous in the young, but not always discernible in 

 the adult : foot extensile : c/iUs or branchial processes, when 

 present, always external, placed upon the back or sides, sym- 

 metrical, and arranged in plumes, tufts, or papillae; in the 



