Fam. 1, Plate 9. 



Figs. 1 to 9. 

 DORIS ASPERA, Alder and Hancock. 



D. ovata, alba, pallio tuberculis validis, clavatis; branchiis 11 parvis, pinnatis, non retractilibus, 

 anum haud propinque cingentibus; capite velato. 



Doris aspera, Aid. and Hanc., in Ann. Nat. Hist., v. 9, p. 32. 

 For. and Hani., Brit. Moll., v. 3, p. 567. 



Hab. Among the rocks between tide-marks ; common on the Northumberland and Durham coasts. 

 Malahide, near Dublin • Ardrossan, Ayrshire, /. A. Burghead, Elgin, plentiful, Geo. Murray, Esq. 



Body about four tenths of an inch in length, ovate, rather depressed, semi-transparent 

 white ; rarely of a yellowish, tinge. Cloak not extending much beyond the foot, covered with 

 rather distant, stout, clavate, flattened tubercles, of nearly equal size, interspersed with a very 

 few smaller ones. The surface between the tubercles has an icy transparency from the spicula 

 shining through : the tubercles are more opaque. Dorsal tentacles rather long, nearly linear 

 or slightly tapering, a little bent backwards, with nine or ten rather distant laminae which 

 have usually a yellowish tinge ; the basis of the tentacles are smooth and colourless : apertures 

 smooth, without sheaths. Branchial plumes eleven, small, simply pinnate, (with five or six 

 pinnae,) transparent white; the anterior ones longest, the posterior pair very short, often 

 scarcely shewing themselves above the tubercles. They are set at a little distance from the 

 anus, leaving a small area. Head with a semicircular veil, smooth at the margin. Foot rather 

 broad, rounded at the ends, and extending a little beyond the cloak behind, when the animal 

 is in progression. It is of a transparent white, sometimes a little yellowish, with a small, oblong, 

 reddish brown patch in the centre from the liver appearing through. There is likewise 

 a pinkish shade on the back of the animal from the same cause. 



The spicula are very variable both in size and form. The larger ones are arranged across 

 the back, and diagonally at the sides, with a few of a slightly waved form running completely 

 round the cloak at a little distance from the margin. Small spicula are clustered into the 

 tubercles radiating at their base. Their usual shape is fusiform, obtusely pointed at the ends, 

 and a little bent in the centre, where there is generally a spur or branch, but many of the 

 smaller spicula, especially in the branchiae and the margin of the cloak, are crucial or dagger- 

 shaped, and this quadriradiate form is found, though less frequently, among the larger kinds. 

 From the crowding of spicula in the skin, and the large hard tubercles, the animal feels firm 

 and harsh to the touch. 



This Doris appears to be' rather local, but is one of the commonest species on the north- 



