ANNELIDES. 
132 
tube bent towards the head, wliich doubtless affords an issue to tlie 
faeces. 1 have found a muscular gizzard in them* * * § . 
Such is the species found along the coast of France, the Sa- 
bella alveolata, Gm. ; Tubipora arenosa,h.-, Ed. XII, Coral., 
XXXVI. Its tubes, united in one compact mass, have their 
orifices regularly arranged like the cells of a honey-comb f. 
Another, the 
Amph. ostrearia, Cuv., establishes its tubes on the shells of 
Oysters, and it is said greatly hinders their propagation. 
It is to this order I suspect that we must refer the 
SvPHOSTOMA, Otto, 
Where, on the superior part of each articulation, is inserted a fasci- 
culus of fine setae, and on the inferior a simple seta, and on the ante- 
rior extremity two fasciculi of strong golden coloured setae. Under 
these setaceous appendages is the mouth, preceded by a sucker sur- 
rounded by numerous soft filaments, which may very possibly be 
branchiae, and accompanied by two fleshy tentacula. The knotted 
medullary cord is seen through the skin. They live buried in mud ;};. 
Hitlierto, the genus 
Dentalium, Lin., 
Has always been placed in this vicinity. The shell is an elongated, 
arcuated cone, open at both ends, and has been compared to the tusk 
of an elephant in miniature. The recent observations of M. Savigny, 
and those of M. Deshayes especially §, have, however, rendered this 
classification exti’emely doubtful. 
The animal of the Dentalia, has neither any sensible articulation, 
or lateral seta?, but is furnished anteriorly with a membranous 
tube, inside of which is a sort of foot, or fleshy and conical opercu- 
lum, which closes its orifice. On the base of this foot is a small 
flattened head, and plumose branchiae are observed on the nape. If 
the opei'culum recall to our minds the foot of the Vermeti and Sili- 
quarlae, which have been placed among the Mollusca, the branchi:je 
strongly remind us of those of the Amphitrites and Terebellae. 
Ulterior observations upon their anatomy, and principally upon that 
of their nervous and vascular system, will resolve this problem. 
* The Sabellari.e, Lam. ; the Hf.rmell.e, Savigny. 
"h This is perhaps the place for the Amphitrite plumusa of Fab., Faun. Grocnl., 
p. 288, and Mi'ill., Zool. Dan., xc ; but their descriptions are so obscure, and agree 
so little with each other, that I dare not attempt to assign it. It forms the genus 
Pherusa, Blainville. 
X Siphostoma diplochaitos, Otto ; — Sijih. imcinata, Aud. and Edw., Litt., de la Fr., 
Annel., pi. ix, f. 1. 
§ Monograph of the genus Dext.vlium, Mem. de la Soc. d’Hist. Nat. de Paris, 
t. II, p. 321, 
