SABELLA. 1, 
to the latter, and whereon the institution of such a genus would be spe- 
cially founded. 
Taking a great and comprehensive view of the general features of the 
animated universe, many analogies in structure and habits will be found 
in animals which now stand far apart, or are totally detached by artifi- 
cial systems. In fact, our attention is to be here directed to individual 
properties, leaving the strict associations of species in genera to future 
labourers. 
The Sabella belgica or Amphitrite awicoma extends to four inches and 
a half in length, by about three quarters of an inch at the shoulder; and 
the tube in which such a specimen dwelt was a hollow conic frustrum, 
five inches long, tapering regularly downwards. 
Never having possessed a specimen in its highest vigour, I can only 
say, that in general structure and in habits, it admits of comparison to 
the Terebella arenaria in many points. 
The anterior portion is distinguished by a flattened face, wherein the 
mouth is situated ; two pair of flattened gills or branchie appear on each 
side of the head, with numerous tentacular organs, not extending far. Two 
gilded fans, somewhat like a comb, rise from the head, consisting of eleven 
or twelve short teeth. The head is presented as a spherical segment at the 
orifice of the tube. It issues from a frill of four segments, more distinct 
than any others, with pencils or bristles from their sides. Other fourteen, 
also with pencils, compose the rest of the body, which terminates by a 
large scoop, exhibiting rudimental segments indenting the back. The 
general hue of the animal is reddish, the branchiz bright vermilion, and 
a vivid red vessel traverses the body. 
This creature constructs a very delicate tube, as thin as paper, ex- 
clusively of the grains of sand agglutinated jtogether in an extraordinary 
manner. The thickness of the side does not exceed a single grain, each 
lies in its own proper place, and the whole is lined with the slightest 
silken coating. The sand being collected at the orifice of the tube, its 
tenant, chiefly by means of the tentacular organs, selects those which are 
appropriate, and applies them to use. This is done only through the 
night, all the additions being made at the orifice, and as the animal grows, 
