202 TERE BELLA. 
taculum seizes a fragment to be elevated to the orifice, instead of being 
abandoned if too ponderous and unwieldy, two or three others unite 
their efforts in raising the load to its intended position. An empty 
mussel shell, above half an inch long, was thus elevated and secured in 
its place to augment an edifice in progress. 
Great expedition is exhibited in fabricating a tube solely of sand, un- 
der total deficiency of more favourite materials. Then are heavy loads 
dragged towards its naked body, with which the mouth is speedily oc- 
cupied. But shell, as best adapted for the labours of the architect, re- 
ceives a decided preference. 
Some particles of this substance are certainly swallowed, but from 
the dimensions of others incorporated with the edifice, they must be 
combined with adhesive matter for fixture. When recovered from the 
sea, the whole structure consists of a very tough silk covering with the 
fragments of shell. 
Perhaps this animal enjoys distinguished reproductive properties. 
Sundered portions survive a long time, and the lower part of mutilated 
specimens is completely regenerated, as we have seen in the case of the 
Terchella tuberculata. ; 
An immense quantity of spawn was produced by a specimen of the 
Terebella conchilega early in December. It covered the bottom of a nar- 
row jar, and on gross computation consisted of at least 8000 ova or cap- 
sules, perhaps imbedded in albuminous matter, invisible from transparence 
or tenuity. The ovum is very minute, spherical, and reddish, of various 
intensity, according to the parent. Under the microscope, an internal 
substance has been discovered within the diaphanous integument, which 
might be the embryo.—Plate XXVIIL. fig. 7, ova. 
Thousands of minute carnation ova, discharged by another specimen, 
perished accidentally in September. 
On one occasion a number of specimens having reached me near the 
end of December, were found much weakened by the impurity of the 
water. Some having been extracted from their tubes as they protruded 
far, one or two produced a multitude of eggs. 
During the earlier days of November, numerous spherules appeared 
