~ principally marine, found on the South Coast of Devonshire. 19 
AMPHITRITE. 
AMPHITRITE VESICULOSA. 
Tas. V. Fig. 1. 
Body with numerous annulations of a pale dull orange colour 
minutely speckled with yellowish white; a broad indistinct stripe 
down the back, in the middle of which is a depressed line as far 
as the ninth joint, where it turns transversely to the left side and 
is lost ; the eight anterior joints are destitute of the dorsal de- 
pression, and on this part the branchia and fasciculi are most 
conspicuous : tentacula two, furnished with about twenty-eight 
long ciliated fibres each, similar in shape to those of A. venti- 
labrum, but of an olive-green mottled with gray, and partly 
disposed in bands, when the plumes are extended : these do not 
form a regular circle when expanded, like A. ventilabrum, but ap- 
pear sub-convoluted, the under part turning inwards; at the 
point of each ray is a dark purplish vesicle, most conspicuous 
on the anterior ray of each plume, terminated by a short hyaline 
appendage: the mouth ringent: lips whitish, furnished with two 
slender feelers or cirri: behind the plumose tentacula is a scal- 
loped membrane surrounding the anterior end ; this, except the 
lower division, is white. 
Length six or seven inches ; diameter of the largest part above 
one fourth of an inch. : 
This new and beautiful species, like most others of the genus, 
prepares a tube for its habitation, the internal texture of which 
-is coriaceous like that of A. ventilabrum, generally described as 
Sabella penicellus, but the external part is invariably coated with 
much coarser sand, intermixed with fragments of shells. Length 
of the tube ten or twelve inches. _ 
D2 3 The 
