DOTO FRAGILIS, Fokbes.
D. luteo-fdsca vel olivacea; velo fastigiis duobus lateralibus ; vaginis tentaculorum sursum expansis;
braDcbiis utrinque 9, robustis, ovato-ccraicis, tuberculorum seriebus 7—9 obsessis.
Tritonia pinnatifida, Johns., in Loud. Mag. Nat. Hist., v. 8, p. 61, f. 4.
Melibosa pinnatifida, Johns., in ‘Ann. Nat. Hist., v. 1, p. 116.
(Doto) fragilis, Forbes, Mai. Mon., p. 4, pi. 1, f. 4.
Hab. In deepish water, generally in the coralline zone. Berwick Bay, Dr. Johnston. Newbiggin
and Cullercoats, Northumberland; and Whitburn, Durham, J. A. and A. H. Ballaugh, Isle of Man.
Professor E. Forbes. Clew Bay, County Mayo, W. Thompson, Esq. Oban Bay; Lamlash Bay, Arran;
Torbay; and Fowey Harbour, Cornwall, J. A.
Body about an inch in length, linear, and rather stout, nearly opaque, of a brownish-
yellow colour varying to olive, with a few tubercular yellow spots along the top of the back,
and a few clustered white ones on the sides below the branchiae. Tentacles of a rich olive
brown, long, filiform, and tapering; issuing from wide trumpet-shaped sheaths, a good deal
expanded in front, and waved at the margin. They are placed far forward, and close together.
Veil short, a little arched in front, produced and rounded at the sides. An elevated ridge
runs from the base of each tentacular sheath along the sides of the veil, terminating before it
reaches the margin. Branchice nine pairs; large, ovate, stout, and closely set on the
back; they are attached by a broad base, scarcely pedunculated, and have somewhat of a
pine-apple form. The papillae covering their surface are in seven to nine rows, with a
terminal papilla at the apex: the larger circles contain ten or twelve papillae each. They are
obtusely pointed, and capable of considerable elongation; generally they are of a nearly
uniform yellowish-brown, sometimes yellowish or greenish-olive; the upper portion of each
is usually paler than the lower, and has a granular appearance; they are very minutely
freckled with white. Foot of a pale yellowish olive, rounded and slightly indented in front,
and tapering to a point behind.
This fine species was first noticed by Dr. Johnston, who took it for the Boris pinnatifida of
Montagu, which we have elsewhere given our reasons for considering a variety of B. coronata.
The terminal spot on the papillae is never found in Boto fragilis. This species appears to be
pretty widely diffused in the British seas, but has not yet been noticed by continental
naturalists. It is generally found on corallines, especially on Antennularia antennina, at the
roots of which, one or two of these mollusks may frequently be found nestling, but so near
is their colour to that of the zoophyte, that they can scarcely be observed without a careful
inspection. They appear to feed upon this zoophyte, and it also affords them a place*of