1869.] DR. J.S. BOWERBANK ON SILICEO-FIBROUS SPONGES. 91 
The continuous reticulating fibre of the skeleton is smooth and 
slightly compressed; but there are numerous stout branches pro- 
jected from it that are full of large tuberculations, so that they very 
closely resemble the young budding antlers of a stag which are being 
renewed after the old ones have beenshed. There are also occasion- 
ally small short groups of tubercles on the angles of the reticulating 
skeleton ; but these are probably an incipient state of the large 
tuberculated branches which are projected in such great numbers 
into the interstitial cavities of the sponge. These organs apparently 
supply the place of auxiliary fibres and the rectangulated hexradiate 
spicula so plentiful in other species of Dactylocalyx, but which 
appear to be totally absent in this one. The numerous fasciculi of 
long slender acerate spicula also appear to replace the rectangulated 
hexradiate ones in their office of supplying support to the interstitial 
membranes of the sponge in the larger spaces within the skeleton ; 
a few single ones are frequently seen passing amid the reticulations 
of the skeleton in directions either horizontal or diagonal to the 
surface. 
During a visit to the British Museum on the 23rd of October, 
1868, I was fortunate enough to find a second specimen of this spe- 
cies, from Formosa by Mr. Swinhoe. It differs materially in form 
from the type one that I received from my late friend Mr. Pratt. 
It is a much less developed sponge; but what there is of it is on a 
larger scale; and fortunately the basal attachment, wanting in the 
type specimen, is in a perfect condition. It is seated on one end of 
a small mass of what appears to be sandstone, the under surface of 
which is covered by serpule. On the sandstone at the base of the 
sponge there is a cream-coloured patch of a compound tunicated 
animal, about 14 inch in length and ? inch in breadth. The base of the 
sponge is 2 inches by 14 inch in diameter ; half an inch above the at- 
tachment the specimen is contracted (and at that part the development 
of the cup commences), and it expands slightly upward; the height 
of the specimen is about 3 inches. The sponge is fortunately in 
very nearly as fine a state of preservation as when taken from the 
sea; and every organ that is found in the type specimen appears 
in abundance in the one from Formosa. In truth, portions of the 
structures taken from the one specimen cannot, by microscopical 
examination, be distinguished from those mounted from the other. 
There are some points in the state of the two specimens that are 
very instructive. ‘Thus in the type specimen the porous system is 
in a beautiful condition, and the numerous pores in the areas are all 
open, while in the corresponding portions of the dermal membrane 
in the specimen from Formosa they are entirely closed; so that the 
important character of the congregation of the pores in areas could 
not have been determined from the latter specimen alone. 
The acquisition of this specimen from Formosa is in favour of Mr. 
Pratt’s belief that the type one was really an East-Indian specimen. 
DactryLocatyx Masont, Bowerbank. 
Sponge sessile, sinuously fan-shaped; surface even, margin 
