fill up the only gap that would otherwise have remained in our illustrations of generic forms.
This “ singular and gaudy animal” as Montagu has not inappropriately called it, attracts the
observer at first sight by the decided character of its orange and black markings, which give
it a harlequin-like appearance. The specific character inserted in our Synopsis, which was
printed off before we had seen the animal, will be found to differ in some respects from that
given above. The former was taken from Montagu’s description and figure, which we had not
perfectly understood. The “ anterior end ” “ extending each side into an angular lobe,” we
had taken to be a bilobed veil; but this appearance is caused by the extended angles of the
foot, which in the figure are represented as forming a part of the head. Montagu has also
made a mistake, as Mr. Thompson has pointed out,* in the number of the branchial plumes ; in
this respect departing from his usual accuracy.
Two specimens were obtained by Mr. Thompson at Weymouth, in the summer of 1854,
by dredging, in about ten fathoms water. The first, he states, lived with him about six
weeks; the second, which was sent to us, survived a considerable time, though in a sickly
state. Mr. R. Q.. Couch informs us that he found two specimens of Thecacera pennigera several
years ago on the Cornish coast.
The jaws and tongue of this species very closely resemble those of Polycera
quadrilineata.
Eig. 1, 2, 8. Thecacera pennigera, different views.
4. A tentacle with sheath.
5. Two of the branchial plumes, much enlarged.
6. A jaw.
7. A row of lingual spines.
8, 9. Spicula.
* Ann. Nat. Hist., 2d series, v. 14, p. 237.