1120 
DE. J. S. BOWEEBANK ON THE ANATOMY 
cation of their presence in any of the secondary series. I first described these structnral 
peculiarities in a paper read before the Microscopical Society of London, January 27, 
1841 ; and it is published in vol. i. p. 32, plate 3, of then: ‘Transactions.’ 
I have met with numerous instances of the occurrence of this structural ari’angement 
of the skeleton in sponges from Australia and the Mediterranean ; but their well-washed 
condition has left them with but very few capabilities for specific distinction. 
I propose to adopt De Blainville’s name Halispongia to designate this genus, the 
characters of which are as follows : — 
Halispongia, De Blainville. 
Skeleton kerato-fibrous. Fibres solid ; primary fibres compressed, containing an irre- 
gularly disposed series of spicula. Secondary series of fibres unsymmetrical, cylin- 
di’ical, without spicula. Plate LXXIV. fig. 11. 
Suborder III. Solid, entirely spiculate, kerato-fibrous skeletons. 
Chalina, Grant. 
Skeleton fibrous. Fibres keratose, solid, cylindrical, and interspiculate. Eete symme- 
trical ; primary lines radiating from the basal or axial parts of the sponge to the 
distal portions. Secondary lines of fibre at about right angles to the primary ones. 
The type of this genus, Halichondria oculata, Johnston, differs so materially in the 
structui’e of its skeleton from that of the type of Halichondria, H. jpanicea, Johnston, 
that it becomes necessary that a distinct genus should be established to receive it and 
other closely allied British species. The skeleton consists of a solid cylindrical keratose 
fibre, enclosing a single or compound series of spicula, imbedded at or near its centre, 
and disposed in lines parallel to its axis, thus forming a structural group intermediate 
between that of Halichondria jpanicea and Spongia officinalis. 
In the sponges of this genus the spicula are decidedly subservient to the fibre, which 
is always cylindrical, and generally very uniform in its diameter throughout the whole 
of a section made at right angles to its surface; while in the nearly allied genus, 
Xsodictya, the reverse is the case, the spicula being the essential basis of the skeleton, 
while the surrounding keratode, although often abundant, is still only the subservient 
cementing medium of the skeleton, and never assumes the decidedly cylindrical form of 
that of the fibre of Chalina. 
In the Edinburgh Encyclopaedia, vol. xviii. p. 844, Dr. Geant proposed the name 
Halina to represent those species which were designated Halichondria by Dr. Fleming, 
and subsequently by Dr. Johnston in his ‘History of British Sponges;’ but as I have 
akeady proposed to restrict the term Halichondria to those species which agree in struc- 
ture with the original type of that genus {H. panicea, Johnston), it becomes necessary to 
select other names to represent the sponges which difier essentially in their structure 
from that type, and I therefore propose to adopt Dr. Geant’s genus Chalina, designated 
