396 ANNELIDES. 



Ophelina, Sav. 

 Body rather thick and short, the rings ill-defined, bristles scarcely visible, and long cirrhi serving 

 for gills upon two thirds of its length ; the mouth containing a dentelated crest at the palate, lips sur- 

 rounded with tentacles, of which the two uppermost are larger than the rest. 

 Hereabouts should probably be placed the Nereis prismatica and bifrons of Fabricius. 



Cirrhatula, Lam. 

 A very long filament serving for gills, and two little bundles of bristles at each articulation of the 

 body, which are very numerous and much serrated, together with a collar of long filaments around the 

 neck. Head ill-defined, with neither tentacles nor jaws. 



Lumbricus cirrhatus, Otto, from which the Terebella tenticulata, Montagu, and the Cirrhinereisfdiger, Blainville, 

 do not appear to me to differ generically. 



Palmyre, Sav. 



Distinguished by their upper bundle composed of large flattened bristles disposed like a fan, and 

 brilliant as the most polisbed gold ; the inferior bundles small ; their cirrhi and gills not very distinct. 

 They have a lengthened body, and two long and three very small tentacles. 



One only is known, from the Isle of France, two inches in length, the P. aurifera, Savigny. 



Aphrodita, Linn. 



Easily known from the rest of this order by two longitudinal ranges of broad membranous scales, 

 covering the back, to which the name elytra has been given without much reason, and under which 

 the gills lie concealed in form of little fleshy crests. The body is generally flattened, and shorter and 

 broader than in other Annelides. A very thick and muscular oesophagus is observable on dissection, 

 which is capable of being reversed into a trunk externally ; the intestine is unequal, and furnished on 

 each side with a great number of branched cceca, the extremities of which are fixed between the bases 

 of the packets of silky bristles which serve for feet. 



M. Savigny distinguishes among them the 



Halithea, — 

 Wherein are three leaflets, between two of which is a very small crest, and which also has no jaws. 



There is one upon our coasts, which is among the most beautifully coloured of animals {Aphrodita acideata, 

 Linn.) Its form is oval, six or eight inches long, and two or three broad. The scales of its back are covered 

 and concealed by a substance resembling tow, which originates at its sides : the latter have also groups of stout 

 spines, which partly pierce the tongue, together with bundles of flexible bristles, as brilliant as gold, and change- 

 able to every hue of the rainbow. The colours they present are surpassed in beauty neither by the scale-like 

 feathers of the Humming-bird, nor by the most brilliant gems. Below them is a tubercle bearing three groups 

 of spines, of three different thicknesses ; and finally, a fleshy cover. There are forty of these tubercles on each 

 side, and between the two first are two little fleshy tentacles ; besides which there are fifteen pairs of broad scales, 

 which are sometimes bulged upon the back ; and fifteen small branchial crests on each side. 



[The animals of this group, which greatly resemble, in form, the Euphrosine laureata, figured in a preceding 

 page, are well known under the name of Sea Mice, and are often thrown upon the beach after a gale of wind. In 

 some species the lateral setse exhibit a beautiful structure, admirably fitting them for weapons of defence, being 

 barbed on each side at the tip ; but, in order to prevent the injury which might occur to the animals, in consequence 

 of the power it possesses of retracting these seta?, each is inclosed in a smooth, horny sheath, composed of two 

 blades.] 



Some species have no tow-like substance on the back, which are the Halithits hermiones of M. Savigny, and form 

 the genus Hermione of M. de Blainville. There is one in our seas, the Aphr. hystrix, Savigny. 



Another division of Aphrodita is the 



Polynoe, Sav. (Eumolpe, Oken), — 

 Having no scales on the back, and five tentacles, together with strong corneous jaws, within the pro- 

 boscis. 

 Several small species inhabit our coasts. 



Sigalion, And. and Edw., — 

 Presents a more elongated form than other Aphrodites, with cirrhi upon all the feet. 



Acoetes, Id., — 

 Have cirrhi which alternate with the elytra for a considerable space, and stronger and better dentelated 

 ;aws. 



