ANNULATA. 206" 
Annélides dorsibranches of Cuvier, whilst, however, in a natural arrange- 
ment it might better remain with the Amphitrite, Ann. des Sc. nat. sec. 
Sér. x. Zool. p. 208. 
** Naked, roving. 
(Commonly Notobranchiate, Dorsibranches Cuv.) 
Family VII. Arenicole (Zelethuse Sav.) Rudiments of feet 
of a dorsal fasciculus of sete: and a ventral transverse tubercle with 
sete very minute, plane, incurved. Branchiz arborescent in the 
middle of the body, with a double row at the sides of fasciculi of 
dorsal sete. Head not distinct ; eyes and jaws none. 
Arenicola Lam. Body elongate, with segments subdivided by 
transverse folds, incrassated forwards, becoming smaller backwards, 
without sete or other appendages behind the last pair of branchie. 
Mouth terminal supplied with a proboscis retractile, papillose. 
Sp. Arenicola piscatorum, Lumbricus marinus L., Nereis lumbricoides, Pattas 
Nov. Act. Petrop. 1. 1788, p. 223, Tab. v. f. 19, 19°; Home Phil. 
Transact. 1817, Pt. 1. Tab. 3; OxEn, Isis, r8r7, p- 469, with fig.; AuDourn 
and Mitng Epwarps, Ann. des Sc. nat. Tom. 30, 1833, Pl. 22, fig. 8. 
This species has thirteen pairs of gills. It lives in deep canals excavated in 
the sea-sand, which the worm forms with its head, whilst the sand is 
swallowed and passed through the intestinal canal ; this worm is flesh- 
coloured, sometimes blackish (Arenicola carbonaria Lac#), and exudes a 
yellow fluid on being touched. Fishermen use it as bait to catch shell-fish 
with the hook. Arenicola branchialis Aub. and Epw. 1.1. fig. 13, has nine- 
teen or twenty pairs of gills, and is smaller than the former. Arenicola 
Beckii Ratuxr, Fauna Norwegens, p. 181, Tab. vit. f. 19—22, differs from 
the former species by the much more numerous gills and by the rings, 
which lie behind the last pair of gills, possessing bundles of hairs; also the 
anterior part of the body is not incragsated like the former species. It 
seems, therefore, that this species should form a sub-genus, 
Tt seems that the genus Scalibregma RataKr ought to be added 
to the Arenicole : it has four pairs of arborescent branchise (in the 
fourth, fifth, sixth and seventh Segment) with a proboscis not warty ; 
Ll. p. 182, Tab. rx. figs. 15—21. 
Family VIII. Cheetopterina. Anterior and posterior yudiments 
of feet with a fasciculus of dorsal sete, without uncinate sets, the 
middle feet with a dorsal appendage, membraneous, large (bran- 
chial?). Head not distinct; maxille none. 
Cheetopterus Cuv. (Worm elongate, included in a coriaceous 
tube). 
