DORSIBKANCHIAT^. 
139 
Halithea, Sav. 
Where there are tiu’ee tentacula, a small crest between two of 
them, and where the jaws are wanting-. 
A species is found on the coast of France, which, with re- 
spect to its colouring, is one of the most splendid of all ani- 
mals — the ApJirodita aculeata, L. Pall., Misc., VII, 1 — 13. It 
is oval, from six to eight inches in length, and from two to 
three in breadth. The scales on its back are covered and con- 
cealed by a sort of stuff resembling tow, which arises from the 
sides. From the latter also spring groups of stout spines, which 
partly transfix the tow, and fasciculi of flexuous setse of a splen- 
did golden colour, whose changeable tints rival those of the 
rainbow. They are not inferior in beauty to the plumage of the 
humming-bird, or to the lustre of the richest gems. Further 
down is a tubercle from which arise three groups of spines, of 
as many different diameters, and finally, a fleshy cone. There 
are forty of these tubercles on each side, and between the two 
first are two small fleshy tentacula. There are fifteen pairs of 
wide, and sometimes inflated scales on the back, and fifteen 
small branchial crests on each side. 
Some of these Halitliese have none of this tow-like material on the 
back* * * § ; one species — Aphr. hyst7'ix,^di\.^, is found in the seas of 
Europe. A second subdivision of the Aphroditse is that of the 
PoLYNOE, Sav . — Eumolpe, Oken. 
Where there is none of this tow on the 1)ack ; they have five ten- 
tacula, and their proboscis is furnished with strong and horny jaws. 
Several small species are found on the coast of France J. 
The Sigaliones, Aud. and Edw., have a much more elongated 
form, than the other Aphroditae ; each foot is furnished Avith cirri§. 
The Acoetes, Aud. and Edw., are provided with cirri Avhicli 
alternate Avith the elytra || ; their jaAvs are stronger and more deeply 
dentated. 
* Tliey are the Ilalifhees hermioties of Savigny, of Avhicli M. de Blainville lias 
made his genus Hermione. 
i' Littoral de la France, Annel., pi. i, f. 1 — 9. 
J Aphr. squamata, Pall., Misc., ZooL, VII, 14 ; Littor., de la Fr., Annel., pi. i, 
f. 10 — 16 ; — Pohjn. Icevis, And., and Edw., Ib., pi. ii. f. 11 — 18 ; — Aphr. imnctaia, 
Miill., Ver., XIII ; — Aphr. cirrhosa, Pall., Misc. ZooL, VIII, 3 — 6; — Aphr. lepidota, 
Id., Ib., 1, 2 ; — Aphr. clava, Montag., Lin. Trans., IX, vii, which is at least closely 
allied to the Aphr. plana, Miill., Ver., XIX; — Pohjnoe impatiens, SaA%, Eg., Annel., 
pi. 3, f. 2 ; — Poly, muricafa, Id., Ib., f. 1. 
§ Sigalion Mathildce, And., and Edw., Littor. de la France, Annel. 
II Acoetes Pled, Aud., and Edw., Collect, of the Museum. 
