SABELLA. 175 
Different species or varieties of the Sabella are found on the shores 
and in the seas of Scotland. The most superficial observers must have 
remarked agglomerated clusters of sandy tubes, with numerous circular 
orifices, rudely resembling honeycomb ; or they may have seen flattened 
tubes, composed more solidly of particles of sand agelutinated to the sur- 
face of shells, in lines or curvatures over them. Or, it may be, they have 
been struck with some single, perfect, conical tube of larger dimensions, 
neatly constructed entirely of such particles, with or without a slight 
silky lining, but altogether so fragile, as to be qualified to offer very little 
resistance against violence. 
All these, whether weak or strong, solitary or conglomerated, con- 
fined or capacious, are the work of their respective tenants, and occupied 
by animals admitting of some comparision with the Nereis and Spio, but 
of closer resemblances among themselves. 
The Sabella is occupied long and sedulously in fabricating its dwel- 
ling, which, from the first, is never quitted, for it does not seem capable 
of constructing a new one. 
§ 1. SapernA arvEotaRrA—The Honeycomb Sabella—Plate XXV. 
Figs. 1, 2, 3. 
The length of this diminutive architect is nine lines ; thickness above 
one. Body round, composed of numerous segments, with bristles from 
the side of some. A slender caudal appendage, generally folded up on 
the body, terminates its extremity. The anterior extremity of the ani- 
mal is cleft longitudinally, with two stout obtuse halves, each bordered 
by about forty tentacular organs, being eighty im all, on a specimen. 
These organs are extremely flexible, and apparently cartilaginous, under 
the microscope. One surface has a groove in the centre, its remainder 
comes out like a file, which peculiar conformation is more conspicuous 
on the edges. But when completely extended, these organs are pectinate 
on both sides, exactly in miniature like the weapon of the saw-fish, ex- 
cept in colour, as may be discovered by microscopical observation. 
