338 DR, J. S. BOWERBANK ON SILICEO-FIBROUS SPONGES. [ May 13, 
as to cause this genus to be readily distinguished from any others 
with which we are acquainted among the siliceo-fibrous sponges. 
KALIAPSIs CIDARIS, Bowerbank. 
Sponge coating, parasitical, very thin. Oscula and pores unknown. 
Expansile dermal system furnished with foliato-peltate connecting 
spicula, peltate heads more or less mammillated, very various in 
form; shafts short and conical. Dermal membrane furnished 
abundantly with minute incipiently spinous fusiformi-cylindrical spi- 
cula, short and stout, dispersed. Skeleton—basal portion eomposed 
of stout canaliculated cylindrical fibre arranged symmetrically in a 
series of reversed semicircular confluent arches, from the crowns of 
which emanate short stout cidarate prehensile fibres with acutely 
conical terminations. Basal limbs of the arches attenuating and ra- 
mifying irregularly upwards, and terminating at the surface of the 
rigid skeleton in a plane of very complicated non-canaliculated reti- 
form layer of depressed fibres. 
Colour in the dried state white. 
Hab. Parasitic on the base of Oculina rosea, from the South 
Seas (J. S. Bowerbank). 
Examined in the dried state. 
I found this singular and beautiful little sponge on the base of a 
specimen of Oculina rosea from the South Seas in 1855, and figured 
a portion of it in illustration of my paper on the “Anatomy and 
Physiology of the Spongiade”’ published in the ‘Philosophical 
Transactions of the Royal Society’ for 1862, plate 28. fig. 12, 
p- 759, as a specimen of prehensile sponge-fibre ; and also in vol. i. 
of ‘A Monograph of the British Spongiade,’ plate 15. fig. 278, 
p- 80, for the same purpose. 
I also figured seven specimens of the dermal connecting spicula in 
the ‘ Philosophical Transactions of the Royal Society’ for 1858, 
plate 24. figs. 32-38 inclusive, in illustration of the foliato-pel- 
tate forms of connecting spicula, and described in detail the mode of 
their development from the simple discoid form to their mature and 
most complicated ramified condition, They are also figured in ‘ Mo- 
nograph of British Spongiadee,’ plate 4. figs. 102, 103, and plate 5. 
figs. 104-108 inclusive, in illustration of the terminology. 
The whole sponge, when attached to the base of the coral, did not 
exceed about 3 lines in diameter; and the largest portion obtained for 
examination is nearly square, 2 lines in length, and about 13 line . 
in breadth, and not exceeding =, inch in thickness. Its peculiar 
structure is singularly illustrative of its parasitic habit. I have 
carefully examined many other specimens of Oculina rosea, but have 
never been fortunate enough to find another specimen. 
On several portions of the largest piece of rigid skeleton I found 
one or two of the foliato-peltate spicula adherent and in situ; and 
in the material scraped from the coral matrix immediately surround- 
ing the sponge, they were found in abundance in every stage of de- 
velopment, and along with them numerous very minute fusiformi- 
