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1388 THE ATLANTIC. [CHAP. II. 
to add to its consistency, present singularly elegant forms. 
One of the most complicated is a spicule with six very short 
rays, each terminated by a vase-shaped arrangement of curved 
and fringed siliceous plates. 
All the specimens of Huplectella aspergillum which I have 
seen, with one exception—there may be others of which I am 
not aware—have had the spicules of the skeleton fused togeth- 
er into one continuous net-work, so that the fabric, although 
fragile, retains its form, and will bear some handling. An ex- 
amination of a portion of the skeleton under the microscope 
shows, however, that it was originally composed of distinct spic- 
ules. Each spicule has a very fine central tube running through 
its axis, and all its branches have the like; and in the mature 
skeleton these central tubes remain, indicating the form and 
position of the original spicules, and showing that they are only 
imbedded in and bound together by an external and secondary 
siliceous cement. The exceptional specimen is one of those 
in the excellent Free Museum in Liverpool. In this case the 
fibres and spicules have remained distinct from one another, 
and consequently the skeleton, although the netted lid is com- 
plete and it has all the appearance of maturity, is quite flexible 
and soft. Whether this be a character common to young in- 
dividuals, whether it be an abnormal condition of this single 
specimen owing to deficiency of silica, or some such cause, or 
whether the specimen ought to be regarded as the type of an- 
other species, I am not yet prepared to say. I have seen small 
specimens of the ordinary form with the spicules soldered to- 
gether, apparently perfect, but short and without the lid, and 
I always supposed these to be the young; but from what we 
know of the intimate structure of the skeleton, it would seem 
probable enough that the spicules may remain separate for a 
time in early life during the expansion of the creature and the 
development of its form. 
The fine species (Fig. 29) for which I propose the name Zw- 
