DORSIBRANCHIATA. 283 



EUNICE, Cuvier. 



The branchiae are also plumose, but the proboscis is well armed with three 

 pairs of differently formed horny jaws; each foot is furnished with two cirri 

 and a bundle of setse ; there are five tentacula above the mouth and two on the 

 nape. In some species only do we find two small eyes. 



Eun. giganiea, Cuv. The largest of the known Annulata, being upwards 

 of four feet in length. From the sea of the Antilles. 



After these genera with complex branchiae, we may place those where they 

 are reduced to simple laminae or slight tubercles, or in which they are even 

 replaced by cirri. 



Some of them are still allied to the Eunices, by the strong armature of their 

 proboscis, and their azygous antennae. Such is the 



LYSIDICE, Cuvier, 



Where, with jaws similar to those of the Eunices, and even more numerous 

 and frequently azygous, the only branchiae consist of three tentacula and the 

 cirri. 



AGLAURA, Savigny. 



The jaws of theAglaura are also numerous and azygous, consisting of seven, 

 nine, c.; but their tentacula are either wanting or completely concealed; the 

 branchiae are also reduced to cirri. 



NEREIS, Cuvier. 



The true Nereides have an even number of tentacula, attached to the sides 

 of the base of the head, and a little further forwards two others that are biarti- 

 culate, between which are two simple ones. Their branchiae consist of small 

 lamina? between which is spread a net- work of vessels; each foot is also fur- 

 nished with two tubercles, two fasciculi of setae, one cirrus above, and another 

 beneath. 



In the vicinity of these Nereides are grouped several genera in which the 

 body is also slendpr, and the branchiae are reduced to simple laminae, or even 

 simple filaments or tubercles. The jaws or tentacula are wanting in some of 

 them. 



PHYLI.ODOCE, Savigny. 



The Phillodoces, like the true Nereides, have an even number of tentacula 

 on the sides of the head, and four or five small additional ones before. They 

 are furnished with eyes; their large proboscis, which is studded with a circle 

 of very short fleshy tubercles, presents no jaws, and, what particularly dis- 

 tinguishes them, their branchiae resemble broad leaves, arranged in a single 

 row on each side of the body, and overlapping each other; finely ramified 

 vessels are distributed over them. 



ALCIOPA, Audouin and Milne Edwards. 



The mouth and tentacula nearly similar to those of the Phyllodoces; but 

 the feet, independently of the tubercle which supports the setae and the two 



