Fam. 1, Plate 22.
POLYCERA aUADRILINEATA, Müller, Sp.
P, alba, seriebus 4—9 ]ongitudinalibus tuberculorum flavomm notata; velo cuspidibus 4, elongatis,
flavo terminatis; branchiis 7—9, pinnatis, lobis branchialibus, utrinque 1, linearibus.
Doris quadrilineata, Mull., Zool. Dan., v. 1, p. 18, pi. 17, f. 4—6, and v. 4, p. 23, pi. 138, f. 5, 6.
Gmel., Syst. Nat., v. 1, p. 3104.
cornuta, Abildg., Zool. Dan., v. 4, p. 29, pi. 145.
flava, Mont., in Linn. Trans., v. 7, p. 79, pi. 7, f. 6.
Polycera lineata, Eisso, Hist. Nat. de FEur. Merid., v. 4, p. 30, pi. 1, f. 5.
flava, Flem. Brit. Anim., p. 283.
ornata, D'Orb. in Guer. Mag. de Zool., v. 7, p. 9, pi. 107.
typica, Thomp., in Ann. Nat. Hist., v. 5, p. 92, pi. 2, f. 5.
quadrilineata, Idem., pi. 2, f. 6.
Alder, in Ann. Nat. Hist., v. 6, p. 338, pi. 9, f. 1— 6.
Yerany, Cat. Anim. Inv. Gen., p. 16.
comuta, Loven, Ind. Moll. Scand., 6.
Hab. Among small sea-weeds in pools between tide-marks, and in shallow water. Coasts of
Devonshire and Cornwall, frequent. Scarborough, plentiful, J. A. Strangford Lough, TV. Thompson,
Esq. Roundstone Bay, Galway, Professor E. Forbes. Dublin Bay and Malahide, J. A. Whitley and
Cullercoats, Northumberland; Marsden, Durham, J. A. and A. H. Near Cumbray Island, Frith of
Clyde, Rev. D. Landsborough. Isle of Man, J. A.
Body from half to three quarters of an inch in length, nearly linear, slightly compressed,
swelling a little in the middle, and tapering to a point behind; smooth, transparent, and
usually white, but sometimes spotted or lineated with black, and always with rows of yellow
tubercles. Tentacles linear or subclavate, broad at the base, and a little bent backwards
above, with the mucro much produced; the upper half is yellow, with about nine or ten
laminae, nearly meeting in front; the lower part is smooth, and usually white, but, in some of
the varieties, black. Frontal veil rather expanded, and adorned with four elongated and
pointed filaments of a golden yellow or orange colour. Head inferior, with a small lobe on
each side. From the margin of the veil a row of yellow or orange tubercles runs on an
elevated ridge along each side of the back to the branchial lobes; another row occupies the
centre of the back, and there is also a similar row on each of the sides: these five rows have,
in finely developed specimens, less perfect intermediate rows, increasing the number to nine.
The tubercles are sometimes confluent, forming continuous yellow stripes, and in the variety
first figured by Müller, the tubercles, in four of the principal rows, are united by black lines;
hence the name of quadrilineata. A few tubercles, ending in a yellow line, occupy the ridge