DORIS TUBERCULATA. 



thickly covered with flattish, spiculose, unequal tubercles, the smaller ones being very 

 numerous and much less than the others : it extends considerably beyond the foot, and has 

 the margins rather thickish ; the under side is smooth. Dorsal tantacles slightly conical, 

 yellow, and strongly laminated above, smooth, transparent, and nearly colourless below. 

 The laminse are upwards of twenty, alternately large and small; the latter not extending 

 so far forwards as the former. Branchial plumes nine, tripinnate, recurved, large and spreading ; 

 much undulated in outline, and forming an incomplete circle round the anus, open behind. 

 They are transparent, obscure white, with a purple or lilac tinge at the edges, faintly freckled, 

 and can be completely retracted within a cavity, the margins of which close over them. 

 Head rather small, with two small tubercular oral tentacles. Foot broadish, rounded and 

 grooved in front, less broadly rounded behind, and of a lemon-yellow or orange colour, 

 with the liver appearing through the centre. 



Spicula numerous, rather small in proportion to the size of the animal, fusiform, bent in 

 the centre, and bluntly pointed at the ends, rarely with the surface slightly nodulous : those 

 in the tubercles are small and more irregularly bent than the others.. The heart pulsates 

 about twenty-eight times in a minute. 



Doris tuberculata is a well-known species, common on all parts of the British coast ; 

 and though not so plentiful as some of the smaller kinds, it is, on account of its conspicuous 

 size, much more readily observed, and is often the only Nudibranch with which the casual 

 visitors of our sea-coasts are acquainted. It is generally found among rocks about half-tide 

 level, and from thence down to low-water mark. Its favorite resort is within the crevices 

 or under the shelving portions of rocks, hung with small sea-weeds and zoophytes, and 

 incrusted with sponges, on which it feeds. In such places its very beautiful spawn may 

 frequently be observed in the spring or early summer, suspended in an inverted cup- or vase- 

 form, winding into a spiral of about three volutions, with the margins slightly waved. It 

 consists of a broad gelatinous riband attached by one of its edges. When uncoiled, we have 

 found it to measure as much as nine inches in length and nearly an inch in breadth. The 

 ova are placed in transverse lines united in pairs, and amount to about fifty thousand in one 

 mass of spawn. More than one of these masses are generally deposited by the same 

 individual in a season. M. Bouchard Chantereaux has found his Doris argus, which is 

 probably a variety of this species, to produce a coil of spawn of twelve inches in length, and 

 he reckons the eggs at eighty thousand. Dr. Johnston met with the spawn of Doris tuberculata 

 winding round the stem of a tangle in a spiral frill, and Sir J. G. Dalyell figures a similar 

 elongated spiral, evidently the spawn of this species. 



This is a very sluggish animal, seldom changing place when kept in confinement, and 

 crawling very slowly. In its contracted state, as it is .usually seen amongst the rocks, it 

 is an unshapely and unattractive animal, being frequently cramped up to suit the inequalities 

 of the surface to which it adheres, and to which it holds so tightly that much force is 

 required to remove it. When placed in a vase of sea-water, however, and its plumes allowed 

 to expand, it is by on means devoid of beauty. 



The range of this species is rather uncertain, as the synonyms of continental authors 

 cannot be relied upon. It appears to be equally common on the northern and western shores 

 of France as with us, but we have no decided evidence of its occurrence in the Mediterranean, 

 as the species called Doris tuberculata by authors describing the productions of that sea is 



