DOKSIBRAKCHIAT.E. 139 



Halithea, Sav. 



Where there are three tentacula, a small crest between two of 

 them, and Avhere the jaws are wanting. 



A species is found on the coast of France, wliicli, with re- 

 spect to its colouring, is one of tlie most splendid of all ani- 

 mals — the Aphrodita aculeata, L. Pall., Misc., VII, 1 — 13. It 

 is oval, from six to eight inches in length, and from two to 

 three in breadth. Tlic 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 setae 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 Halitheae have none of this tow-like material on the 

 back*: one species — Aphr. hi/sfrix,Sa.y.\, is fovmd in the seas of 

 Evirope. A second subdivision of the Aphroditae is that of the 



PoLYNOE, Sav. — EUMOLPE, OkcU. 



Where there is none of this tow on the back ; they have five ten- 

 tacula, and their proboscis is fiuTiished 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 with cirri §. 



The AcoETES, Aud. and Edw., are provided with cirri which 

 alternate with the elytra || ; their jaws aie stronger and more deeply 

 dentated. 



* They are the Halithecs hermiones" of Sa\-igny, of which M. de Blainville has 

 made his grenus Hermione. 



f Littoral de la France, Annel., pi. i, f. 1 — 9. 



+ Aphr.squamata, Pall., Misc., Zool., VII, 14 ; Littor., de la Fr., Annel., pi. i, 

 f. 10 — 16 ; — Polyn. lacis, Aud., and Edw., lb., pi. ii. f. 11 — 18 ; — Aphr. punctata, 

 Miill., Yer., XIII ; — Aphr. cirrhosa, Pall., Misc. Zool., VIII, 3 — 6 ; — Aphr. lepidota, 

 Id., lb., 1, 2 ; — Ajjhr. clava, Montag., Lin. Traus., IX, vii, which is at least closely 

 allied to the Aphr. plana, Miill., Ver., XIX; — Polynoe impatiens, Sav., Eg., Annel., 

 pi. 3, f. 2 ; — Pohj. muricata, Id., lb., f. 1. 



§ SigaJion Mathilda, Aud., and Edw., Littor. de la France, Annel. 



II Acuetes Pkei, Aud., and Edw., Collect, of the Museum. 



