22 CLASS ANNELIDA. ' 



N. longa, Ott. Fab., which M. Savigny places with N.Jlava, 

 in his genus Eteone : all these annelida should be carefully 

 examined afresh, according to the detailed method of M. 

 Savigny. 



We must not confound these phyllodocse of M. Savigny 

 with those of M. Ranzani, which are allied to the aphroditae, 

 and particularly to the polynoae. 



Alctopa, Aud. and M. Edwards. 



They have pretty nearly the mouth and tentacula of 

 phyllodoce ; but their feet, independently of the tubercle 

 which supports the bristles, and the two foliaceous cirrhi, or 

 gills, present two branchial tubercles, which occupy their 

 superior and inferior edges, Alciopa Reynaudii, Aud. and 

 Edw. Of the Atlantic Ocean. The pretended Nais Rathke, 

 Soc. d' Hist. Nat. de Copenh. v. part i. pi. iii. f. 15, may very 

 probably be an Alciopa. 



Spio, Fah. and Gmel. 



The body is slender ; there are two very long tentacula, 

 which have the appearance of antennae, eyes in the head, and 

 on each segment of the body a gill on each side, in the form 

 of a simple filament. These are the small worms of the 

 Arctic Ocean, which inhabit membranous tubes, Spio seti- 

 cornis, Ott., Fab., Birl., Schr. VI. v. 1 — 7; Spio Jllicornis, 

 ib. 8 — 12. The Polydor^, Bosc. vers. I. v. 7,, appear to 

 me to belong to this genus. 



Syllis, Sav., have tentacula of an uneven number, articu- 

 lated like the beads of a rosary, as well as the superior cirrhi 

 of the feet, which are very simple, and have but a single 

 parcel of bristles. It appears that there are some varieties 

 relative to the existence of their jaws, Syllis monilaris, Sav., 

 Eg. Annel. iv. f. 3. copied. Diet, des Sc. Nat.— N. B. The 

 Nereis armillaris, Mull. vers. pi. ix., of which, without 



