1869.] DR. J.S, BOWERBANK ON SILICEO-FIBROUS SPONGES. 325 
illustrations to my paper “ On the Anatomy and Physiology of the 
Spongiade”’ (Phil. Trans. for 1862, plate 34. figs. 17 & 18), 
and also in vol. i. of ‘ Monograph of British Spongiadz’ (plate 35. 
figs. 340 & 341). The latter figure in each of these quotations 
represents one of the gemmules filled with granular matter, x 666 
linear. A small portion of the skeleton from the Porto Rico speci- 
men is also figured in Plate XXII. fig. 1, of the present work, x 108 
linear, to exhibit the abundance of these organs iz situ. In this 
portion of the skeleton (fig. 1, Plate XXI., representing the general 
contour of the skeleton) the gemmules are very few in number, the 
original of the figure being from a different portion of the sponge. 
IpHITEON BEATRIX, Bowerbank. 
Aphrocallistes beatriz, Gray, Proc. Zool. Soc. 1858, p. 115, pl. xi. 
Sponge fistulous, branching irregularly. Surface of the rigid 
skeleton undulating or tuberous. Oscula congregated, terminal. 
Pores and dermal system unknown. Skeleton symmetrically ra- 
dial; radii short and stout ; areas of the rete mostly six-sided, spaces 
within triangular ; fibre cylindrical; central umbo of the areas spi- 
nous. Inhalant spaces of the skeleton-surface armed with stout 
elongo-conical, acutely terminated, arl abundantly spinous defensive 
fibres. External defensive spicula of the skeleton acerate, distal por- 
tions incipiently recurvato-spinous, long and slender, very numerous ; 
and also stout subfusiformi-cylindrical, entirely spinous spicula, few 
in number. Interstitial spicula attenuated rectangulated hexradiate, 
large and small; axial ray of the latter occasionally spinous at one 
or both of its terminations; spines very long and slender, curving 
towards the extremities. Spicula of the membranes :—Tension- 
spicula acerate, very slender. Retentive spicula acerate, verticil- 
lately spinous ; verticilli few in number; spines large and acute, 
and also porrecto-spinulo-multiradiate spicula with slightly attenu- 
ated shafts ; radii from three to six or more, slender and minute, few 
in number. Gemmules spherical, membranous, irregularly dispersed. 
Colour in the living state unknown. 
Hab. Malacca (Admiral Sir Edward Belcher). 
Examined in the skeleton state. 
Dr. Gray’s description of this beautiful sponge in the ‘ Proceed- 
ings’ of this Society for 1858 is inaccurate in several important 
points. In the first place he describes it as calcareous, whereas 
it is purely siliceo-fibrous. He also states the outer surface to be 
“formed of intertangled transparent spines which inosculate and 
unite with each other at the intersection,’ while the whole of the 
skeleton is formed of a symmetrical network of siliceous fibre. He 
further states that “the end of the main tube is closed with an 
open network formed of spicula,” when in reality it is an intricate 
reticulation of siliceous fibre of a very remarkable structure. Subse- 
quently the author writes, “in this genus the mass of the sponge is 
formed of small spicula, which inosculate and are united together, 
forming a hard mass pierced with numerous closed, small, uniform 
Proc. Zoou. Soc.—1869, No. XXII. 
