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and very large spicula, forming the axial sceleton of a columnar 
eloacal system. 
Gen. n. Isodictya. Sceleton without fibre, composed of a 
symmetrical network of spicula; the primary lines of the sceleton 
passing from the base or centrum to the surface and the secondary 
lines disposed at about right angles to the primary ones. Propagation 
by internal membranaceous aspiculous gemmulae. Als Typus dieses 
artenreichen Genus wird aufgeführt: T. infundibuliformis Bow. (Dürfte 
wohl meist mit Reniera Schm. zusammenfallen.) 
Spongilla L. Sceleton without fibre, compesed of a symme- 
trical network of spicula; the primary lines of the sceleton passing 
from the base or centrum to the surface and the secondary lines 
disposed at about right angles to the primary ones. Reproductive 
organs ovaries coriaceous and abundantly spiculous. Alle Arten 
gehören dem Süsswasser an. Mit Sp. fluviatilis Johnst. als Typus. 
Subord. 4. Spieulo-fibrous sceletons. Regularly fibrous. Fi- 
bres filled with spicula. 
Gen. n. Desmacidon. Sceleton fibrous, irresularly reticu- 
lated. Fibres composed entirely of spicula arranged in aceordance 
withi the axis of the fibre, cemented together and thionly coated 
with keratode. Hieher als brittische Arten: Hal. aegagropila Johnst. 
und H. fruticosa Johnst. 
Gen. n. Raphyrus. Sceleton fibrous, but not horny. Fibre 
composed of a dense mass of siliceous spicula mixed together with- 
out ordre. Einzige Art R. Griffithsii Bow. 
Subord. 5. Compound reticulate sceletons, having the pri- 
mary reticulations fibro-spiculate, and the interstices filled with a 
secondary spiculo-reticulate sceleton. ) 
Gen. n. Diplodemia. Sceleton fibrous; fibres keratose, he- 
tero-spiculous; combined with a secondary sceleton of irregular 
network of spicula; rete unispiculate, rarely bispieulate. Ovaries 
membranous and spiculous. Einzige Art D. vesicula n. sp. aus 
Schottland. 
Subord. 6. Solid: siliceo - fibrous sceleton. Sceletons reticu- 
late. Fibres composed of concentrie layers of solid silex, without 
a central canal. Reticulations unsymmetrical. 
Gen. Dactylocalyx Stutehbury (Iphiteon Mus. Par.). Sceleton 
siliceo-Abrous. Fibres solid eylindrical. Reticulations unsymmetri- 
cal. Eine höchst interessante Form mit kiesligem Fasernetz, die 
als D. pumicea beschrieben wird und von -Barbadoes stammt. 
Subord. 7. Canalieulated silico - fibrous sceletons. Sceleton 
reticulate, symmetrical. Fibres composed of concentrie layers of 
solid silex, with a continuous central canal. 
Gen, un. n. Farrea mit F. occa n. sp. 
