187 
Sabettaria Anglica , Grube, ( S. alveolata , Sav.^ 
Very common within shells, especially the whelk. 
S. Crassissima , Lam. Rare. 
Terebella conchilega, Pall. 
Frequent near low water. 
T. chrysodon Mont. \ 
T. nehulosa , Mont. V Attached to shells, Sec . — not rare. 
T. constrictor , Mont. ' 
I have found two specimens of a minute species with only 
eight tentacles, among tubes of sabellaria, perhaps the young 
of some larger form, they resemble T. ostreata , Dalyell. 
Ops, gen. nov. f One of the names of Cybele.J 
Tube slender, strong but flexible when moist, coated with 
minute, closely imbricated fragments of shell, attached 
edgewise. 
Worm terete, of equal breadth throughout (Vo inch). 
Branchial fans two, terminal, very short, composed of soft, 
thick, pectinated processes, the apices bifid, obtuse, incurved, 
surrounding the mouth like a star, not ciliated. Between 
the fans is a small scoop-like lip. 
Bings distant, the upper one contracted at the apex, with 
lateral tufts of setae, much shorter than the succeeding seg- 
ments, which are six to eight times longer than broad. 
Ventral surface channelled, on each side of it are pencils 
of slender setae: and surrounding all but the ventral aspect 
of each ring, a narroio rough band like a rasp , the surface 
studded with conical papillae. No lateral hooks. 
Anal rings narrower, ending in an obtuse point. 
O. digitaia , sp. nov. Frequent opposite the Whitworth 
guns, near low tide mark, accompanying species of Terebella. 
Tube three to four inches long, tapering a little at each 
end, which is open, as thick as a crow-quill. It has a very 
neat appearance from the uniform size of the shell fragments. 
Intestine simple, undulating, filled with mud and sand. 
Peristome not longer than broad, when closed conical, the 
