154 Leuckart: Bericht üb. d.Leist. in d. Naturgeschichte 



and very large spicula, forming the axial sceleton of a columnar 

 cloacal 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 mem.branaceous aspiculous gemmulae. Als Typus dieses 

 artenreichen Genus wird aufgeführt : T. infundibuliformis Bow. (Dürfte 

 wohl meist mit Reniera Schm. zusammenfallen.) 



Spongilla L. Sceleton without fibre, composed 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. Spiculo-fibrous sceletons. Regularly fibrous. Fi- 

 bres filled with spicula. 



Gen. n. Desmacidon. Sceleton fibrous, irregularly reticu- 

 lated. Fibres composed entirely of spicula arranged in accordance 

 withi the axis of the fibre, cemented together and thionly coated 

 with keratode. Hieher als brittische Arten: Hai. 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 irregulär 

 network of spicula; rete unispiculate, rarely bispiculate. Ovaries 

 membranous and spiculous. Einzige Art D. vesicula n. sp. aus 

 Schottland. 



Subord. 6. Solid siliceo - fibrous sceleton. Sceletons reticu- 

 late. Fibres composed of concentric layers of solid silex, without 

 a central canal. Reticulations unsymmetrical. 



Gen. Dactylocalyx Stutchbury (Iphiteon Mus. Par.). Sceleton 

 siliceo-fibrous. Fibres solid cylindrical. Reticulations unsymmetri- 

 cal. Eine höchst interessante Form mit kiesligem Fasernetz, die 

 als D. pumicea beschrieben wird und von Barbadoes stammt. 



Subord. 7. Canaliculated silico - fibrous sceletons. Sceleton 

 reticulate , symmetrical. Fibres composed of concentric layers of 

 solid silex, with a continuous central canal. 



Gen. un. n. Farrea mit F. occa n. sp. 



