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FAMILIES, GENERA, AND SPECIES, OE THE BRITISH MARINE 



ANNELIDS. 



(ANNELIDA POLYCELETA.) 



Order— POLYCELETA. 



Family I. — Amphinomim:. 



Cephalic lobe rounded or compressed. A median and two lateral tentacles, though 

 the latter may be absent, an elongated dorsal caruncle, and four eyes. Body elongate, 

 oblong or ovate-oblong, feet with the dorsal and ventral divisions widely separated and 

 furnished with cirri. Mouth removed from the tip of the snout ventrally, with 

 modified segments laterally; protrusible proboscis devoid of jaws. Feet peculiarly 

 modified, the dorsal lobe being extended and merged into the dorsum, but with bristles, 

 branchiae, and cirri. Bristles brittle, calcareous, and tubular, with gelatinous contents ; 

 rarely hook-like spines. Buccal apparatus and proboscis large and complex; alimentary 

 canal often with a caacum in front. Anus dorsal. Two posterior appendages. Nerve- 

 cords either lie within the body-wall, the decussation of the oblique muscular bands 

 being beneath them, or the latter are attached at the outer border of each trunk. 

 Oviparous. 



Sub-family — Amphinomina. 



Cephalic lobe rounded, furnished with a median and two lateral tentacles; body 

 elongate; branchiae on the dorsum of the feet, which have their dorsal and ventral 

 divisions widely separated. Bristles brittle, calcareous, tubular, with gelatinous 

 contents. 



Nerve-cords somewhat small and flattened, occupying an area bounded internally 

 by a transverse band of fibres, and externally by the circular muscular layer and the 

 granular layer beneath the cuticle. The oblique muscles are attached at the outer 

 border of each trunk. Intestine simple. 



Savigny in his ' Systeme ' (1820) made the Amphinomse the fourth Family of his 

 first Order Nereids, characterising them as follows :— Branchiae large, complex, 



