ANNELIDA FROM BERMUDA. oe 
Fam. THELETHUSID. 
ARENICOLA Lamarck. 
ARENICOLA CRISTATA Stimpson. 
Stimpson. Proc. Boston Soc. Nat. His., vol. v, p. 114. 
QUATREFAGES. Hist. Nat. des Ann., vol. ii, p.673. 1865. 
The posterior (non-branchiated) segments of this species are set off 
from each other by deep constrictions. 
On the first segment, back of the branchie, the feet are represented 
by two stout conical cirri on either side, distant from each other by 
about the diameter of the base of each. 
On the remaining nine segments there is but a single cirrus on each 
side, and these pass to the ventral surface, and stand close together. 
Fam. CIRRATULID:. 
CIRRATULUS Lamarck. 
CIRRATULUS TENUIS 2. sp. 
(Plate XI, Figs. 56, 57.) 
Head short, bluntly rounded infront; noeyes. First three segments 
without sete or cirri. Third segment a little longer than the fourth; 
as long as the first two together. 
Lateral branchiz begin on the fourth segment, and exist, on the an- 
terior third of the body, on all segments; not so numerous further back. 
Dorsal branchie on the fifth, sixth, and seventh setigerous segments, 
two or three on each side of each segment; not forming a complete 
transverse series, but leaving a naked median space. Branchial cirri 
all long, not differing from each other. 
The set of the anterior segments are capillary in both rami, long, 
delicate, 7-10 in each fascicle. 
At about the fifteenth setigerous segment the ventral sete begin to 
be replaced by uncini, and after a few segments the capillary sete dis- 
appear. There are at first three of the ventral uncini; then two; while 
on the posterior segments there is butonetoeachramus. At about the 
twentieth setigerous segment uncini appear in the dorsal rami; both 
kinds of sete remain to the end. 
The body is convex above, compressed, flattened below; segments 
very short but distinctly defined; from the middle the diameter decreases 
slightly, backward. 
Number of segments, 110. 
Length, 30™™. 
Diameter, 2™™. 
