1096 
DE. J. S. BOWEEBANK ON THE ANATOMY 
Suborder IV. Spiculo-fibrous skeletons. Regularly fibrous. Fibres filled with spicula. 
1. Besmacidon, Bowerbank. 
2. Maphyrus, Bowerbank. 
Suborder V. Compound reticulate skeletons, having the primary reticulations fibro- 
spiculate, and the interstices filled with a secondary spiculo-reticulate skeleton. 
Biplodemia^ Bowerbank. 
Suborder VI. Solid siliceo-fibrous skeletons, reticulate. Fibres composed of concentric 
layers of solid silex ; without a central canal. Reticulations unsymmetrical. 
Bactylocalyx, Stutchbury=^Ai;feo% of the Museum at the Jardin des Plantes, Paris. 
The structure of the fibre in this suborder of siliceo-fibrous sponges is equivalent to 
that in the first suborder of the third order, Keratosa. 
Suborder VII. Canaliculated siliceo-fibrous reticulated skeletons. Fibres composed of 
concentric layers of sohd silex, with a continuous central canal. Reticulations 
symmetrical. 
Farrea, Bowerbank. 
The construction of the fibre of the skeletons of this suborder of siliceo-fibrous 
sponges is the equivalent of the fibrous structure of the fourth suborder of the third 
order, Keratosa. 
Order III. KERATOSA. 
Suborder I. Solid non-spiculate kerato-fibrous skeletons. 
1. Spongia, Linnaeus. 
2. Spongionella, Bowerbank. 
No spicula are secreted in any of the parts of the sponges of this suborder. 
Suborder II. Solid semispiculate kerato-fibrous skeletons. Skeleton partially symme- 
trical ; primary lines of fibre radiating from the proximal to the distal parts of 
the sponge ; fibres containing spicula. Secondary lines of fibres unsymmetrical, 
destitute of spicula. 
The Bahama sponges of commerce are most of them members of this suborder. 
Halispongia, Blainville. 
Suborder III. Skeletons kerato-fibrous ; fibres solid, entirely interspiculous. Skeleton 
symmetrical. 
Chalina^ Grant. 
In this suborder the keratode is the primary material in the structure of the fibre, 
and the spicula the secondary or auxiliary agent. The reverse is the case in the spiculo- 
fibrous tissues of the fourth suborder of Order II. Silicea. 
