284 DR. J. S. BOWERBANK ON THE SPONGIAD&. [Apr. 6, 
very slender. Retentive spicula inequidentato-palmate anchorate, 
congregated in circular groups or dispersed, large and strong ; and 
very minute palmato-inequianchorate, dispersed ; also very minute, 
bidentate, equianchorate, dispersed; and also bidentate, equian- 
chorate, rather large and stout, few in number; also bihamate 
simple and contort large and strong, and the same form very 
minute and slender. Skeleton-fasciculi more or less multispi- 
culous; bases and apices of the component spicula coincident, 
irregularly disposed ; spicula acuate, stout, moderately long; basal 
membrane stout, somewhat coriaceous, abundantly armed with atten- 
uato-acuate entirely spined internal defensive spicula; interstitial 
membranes spiculous ; spicula same as those of the dermal membrane, 
rather sparingly dispersed. 
Colour dull cream-white in the dried state. 
Hab. Straits of Malacca (Commodore Parish, R.N.). 
Examined in the dried state. 
I received six specimens of this very interesting sponge from my 
friend Commodore Parish, who obtained them from the Straits of 
Malacca. The largest measured 33 inches in length by 1? broad, 
and its greatest thickness does not exceed about § of an inch. 
It entirely covers a mass of Cellepora about a j of an inch in thick- 
ness. The surface appears smooth to the eye, but it is really 
minutely hispid. The hispidation is produced by the projection of 
about half the length of the spicula of skeleton-fasciculi; the distal 
ends of each of them separate divergingly, forming an infinite 
number of minute external defensive groups ; as the amount of their 
projection does not exceed +}, inch, this character is only to be ob- 
served in sections at right angles to the surface mounted in Canada 
balsam. This radiating expansion of the skeleton-fasciculi at the 
surface of the sponge, so as to form an efficient system of external 
defence, is on the same principle as the expansion of the distal ter- 
minations of the primary fibres of the skeleton of many species of 
the genus Isodictya, thus exhibiting in a very different mode of the 
construction of the skeleton the same economic design in the pro- 
duction of a series of organs of external defence. In other genera 
where this beautiful mode of adaptation is inapplicable, especial 
systems of spicula are provided to achieve the necessary defences of 
the dermal surface. 
The dermal membrane and the interstitial tissues are remarkably 
rich in defensive and retentive spicula; and I have never found in 
any other sponge so great a number of forms and so much variety of 
size as in this species. The dermal rete is very strongly and com- 
pactly constructed; but the spicula composing it have not their ter- 
minations coincident as in the skeleton-fasciculi. Both forms of 
tension-spicula are small and slender, The hiclavate cylindrical ones 
are ;4, inch in length and ;,}5» inch in diameter; the greater 
number of them are collected into fasciculi containing from five to 
eight or nine spicula ; and others are singly disposed among the rest 
of the spicula. The fasciculi have no especial mode of distribution. 
