54 THREE CRUISES OF THE “BLAKE.” 
in the tubes, such marked peculiarities may occur in their choice 
and application that from a fragment of the tube the builder 
can be inferred with certainty, and the form of c 
the tubes (Figs. 261, 262, 
263) may even be so char- 
acteristic that there is no 
danger of mistaking them 
for other tubes. We have 
examples of this kind 
especially in the Kunicide, 
and also in the Maldanide 
(Fig. 264), Terebellide, Sa- 
bellidze, and Serpulide. In 
determining the distribution 
of the worms, it must be rig. 265. — Cirra- 
Fig. 264.— Maldane remembered that uninhab- tulus melanacan- 
TORIS ited tubes, usually filled by este 
mud or other material from the bottom, may be transported by 
currents. 
Many of the principal types of the littoral annelids have not 
Fig. 266.— Amphinome Pallas. 3. 
been dredged beyond the hundred-fathom line; such familiar 
groups as the Syllide, Nereide, Cirratulide (Fig. 265), and 
Amphinomide (Fig. 266), have no 
representatives at that depth, while 
the Phyllodocide, Ariciide, Tere- 
bellide, and Sabellide extend to 
300 fathoms, and such families as 
the Polynoide (Fig. 267), Eunicide, 
Opheliide, Aphroditide, and Serpu- 
lide live beyond the five-hundred-fathom line, where occur 
also the Ampharetide, many of which live in tubes lined with 
a chitinous layer. 
Fig. 267. —Sthenelais simplex. 48. 
