1132 
DE. J. S. BOWEEBANK ON THE ANATOMY 
thirds combination, and again with not less than a quarter-inch object-glass, and the 
characters of the various tissues in their natural condition be immediately noted. But 
the whole of their minute organs will not be visible by this mode of examination ; and it 
is therefore necessary to mount the same or similar sections in Canada balsam, by which 
means the spicula of the sarcode and other minute organs will become completely visible 
in situ; and the specimens thus mounted will serve as permanent records for the 
cabinet. 
The following are a few examples of the mode of specific description that I propose 
for adoption by naturalists who may investigate the Spongiadae. 
Geantia ciliata, Fleming. 
G. ciliata^ Johnston. 
G. pulverulenta, Johnston. 
Sponge elongately oval, rarely globular, slightly pedicelled ; surface papillated, hispid. 
Cloaca central, cylindrical, nearly as long as the sponge ; armed internally with 
spiculated equiangular triradiate spicula ; spicular ray attenuated. Mouth of the 
cloaca armed with a thick ciliary fringe of very long and slender acerate spicula ; 
base of the fringe supported by large, short and stout fusiformi-acerate spicula. 
Oscula simple, very slightly depressed from the surface of the cloaca, as numerous 
as the interstitial cells. Pores inconspicuous. Interstitial cells: distal termina- 
tions more or less obtusely conical, furnished with a ciliary fringe of slender acerate 
spicula. Skeleton-spicula equiangular triradiate. 
Colour cream-white. 
Hah. Coasts of Great. Britain ; parasitical on fuci; littoral to 8 or 10 fathoms or more. 
Examined alive. 
Pachymatisma JoHNSTOJsriA, Bowerbank. 
Halichondria Johnstonia, Trans. Mic. Soc. London, vol. i. p. 63, pi. 6 ; Johnston’s 
Hist. Brit. Sponges, p. 198. 
Sponge massive, sessile ; surface smooth, undulating into ridges. Oscula simple, con- 
gregated on the elevations. Pores inconspicuous. Dermis crustular, filled with 
ovaria. Dermal membrane pellucid, abundantly spicular; spicula fusiformi-cylin- 
drical, tuberculated, minute. Intermarginal cavities immersed in the dermal crust, 
separate, symmetrical, subcylindrical, valvular at proximal end. Connecting spicula 
attenuate- or cylindro-ternate ; radii variable in form and proportions. Skeleton- 
spicula cylindrical, variable in form and proportions. Spicula of sarcode attenuato- 
steUate ; radii incipiently spinous, rarely fully spinous, or obtuse. Ovaria oval, 
depressed. 
Colour : littoral specimens light to dark slate-grey ; deep-sea specimens pink or red. 
(Captain F. W. L. Thomas, R.N.) 
