506 DR. J. S. BOWEKBANK ON [June 15, 
to the particular species, is apparent—that of allowing a considerable 
amount of expansion and contraction in the dermal system of the 
animal, so that, if the skeletons are rigid, the necessary expansions of 
the dermal organs of the animal may achieve inhalation and exhala- 
tion, as necessary to the sponge as to the higher classes of animals, 
of marine or land-living creatures ; and this is precisely what takes 
place in the dermal system of Alcyoncellum speciosum, but in a more 
complicated and beautiful manner than in any other siliceo-fibrous 
sponge with which I am acquainted. 
There are several other varieties of form of the remarkably con- 
stricted compound floricomous spicula which are figured in the 
‘ Philosophical Transactions of the Royal Society’ for 1857, plate 
Xxvil., and also in plate viii. vol. i. ‘ Monograph of British Spongiade ;’ 
but none of these forms are elevated on the distal portion of the 
shaft of a simple rectangulated sexradiate spiculum, as in Aleyon- 
cellum speciosum. 
In the portion of the specimen mounted in Canada balsam in the 
cabinet of Dr. Miller I found a considerable number of gemmules 
dispersed amidst the tissues ; some were on the skeleton-fibres, while 
others were attached to the interstitial membranes. They were 
membranous and aspiculous, closely resembling the same descrip- 
tion of organs in Dactylocalyx pumicea, as represented in the ‘ Philo- 
sophical Transactions of the Royal Society’ for 1862, plate xxxiv. 
figs. 17 & 18, and also in ‘ Monograph of British Spongide,’ vol. i. 
plate xxv. figs. 340 & 341. They varied in size to a much greater 
extent than those of Dacty/ocalyx. The largest one measured =4, 
inch in diameter; another was =}; inch in diameter; and the speci- 
mens ranging between these two sizes were comparatively numerous. 
Others, equally well developed, measured 5,1; inch; and the smallest 
well-defined one was but 5,5; inch in diameter. 
Thus we have, by the aid of Dr. Miller’s beautiful specimen, ob- 
tained a much more correct knowledge of the anatomy and physi- 
ology of this beautiful sponge than we previously possessed ; and, 
in addition to these interesting facts, a letter published in the ‘Times’ 
April 30, 1875, from Her Majesty’s ship ‘Challenger,’ contains 
some interesting information regarding its habits in its natural state. 
“The regaderas,” as the Spaniards call them, ‘‘ are found at a depth 
of about 100 fathoms. The/Indian lets down his bamboo arrange- 
ment with a strong fine line of Manilla hemp, and pulls it slowly 
over the ground. Every now and then he feels a slight tug; and at 
the end of an hour or so he pulls it in, with usually from five to ten 
‘regaderas’ entangled on the hooks. Huplectella has a very dif- 
ferent appearance, under these circumstances, from the cones of 
glossy network in the British Museum. Its silver beard is clogged 
with the dark grey mud in which it lives, buried to about one third 
of its height ; and the network of the remainder of the tube is covered 
with a pall of yellowish fleshy matter, which gives it a heavy look, 
and greatly diminishes its beauty. he layer of flesh is not so thick 
as we expected, and only slightly masks the form of even the de- 
tailed sculpture of the sponge.” 
