26 CLASS ANNELIDA. i 



branching cceca, the extremities of which are fixed between 

 the bases of the bundles of bristles, which serve as feet. 



M. Savigny distinguishes Halithe^, which have three 

 tentacula, and between two of them one very small crest. 

 They are destitute of jaws. 



We have one of these upon our coasts, which is one of the 

 most beautiful of animals, in point of colour, Aphrodita acu- 

 leafa, L. Pall. Misc. v. ii. 1 — 13. It is oval, six or eight 

 inches long, and two or three broad. The scales of its back 

 are covered and concealed by a sort of stuff resembling tow, 

 which arises from the sides. From these same sides spring 

 groups of strong spines, which partly pierce the tow, and 

 bundles of flexuous bristles, shining with all the brilliancy of 

 gold, and changing into all the tints of the rainbow. They 

 do not yield in beauty to the plumage of the humming-bird, 

 nor to the most lively lustre of precious stones. Lower down 

 is a tubercle, from which spines in three groups issue forth, 

 and of different dimensions, and, finally, a fleshy cone. Forty 

 of these tubercles may be counted on each side, and between 

 the first two are two small fleshy tentacula. There are fifteen 

 pairs of broad scales, and sometimes inflated, on the back, 

 and fifteen small branchial crests on each side. 



Some of these Halitheaj have none of this tow-like stuff on 

 the back, and our seas produce one species of them — Aphrod. 

 hysti'ix, Sav. 



Another subdivision of the Aphrodita is that of PoLYNOE, 

 Sav.jEEMOLPE, Oken, which have no tow on the back; their 

 tentacula are five in number, and their proboscis contains 

 strong and corneous jaws. 



We have several species on our coasts. 



Aphrod. squavwta, Pall. Misc. Zool. vii. 14. Littor. de la 

 France, Annel. pi. i. f, 10 — 6 ; Polyn. Iccvis, Aud. and Edw. 

 ib. pi. ii. f 11 — 18; Aphrod. punctata. Mull. Vers, xiii ; 

 Aphrod. cirrhosa, Pall. Misc. Zool. viii. 3 — 6; A. lepidota, 



