392 M. K. A. Zittel on Fossil Lithistldoe. 



so as to reproduce on a large scale the appearance of a quadri- 

 radiate Lithistid corpuscle. On the surface spicules of the 

 same form and size lie irregularly, forming a covering-layer, 

 sometimes 1-3 millim. in thickness. No free spicules of" 

 different form were observed. 



1. Siphonocodia texta, Rom. Spong. x. 11. Very abun- 

 dant in the Cuvieri-VVdMex of Dohrnten near Salzgitter. 

 Quenstedt gives good figures of it under the name of Eule- 

 spongia texta, Petr. cxxxv. 3-7. 



Siphonocodia hirta^ Rom. Spong. xi. 6, also possibly belongs 

 to this genus. 



Family 3. Anomocladina. 

 Cylindrophyma, Zitl. 



Scypkia auct. 

 Siphonocalia p. p., From. 

 Hippalhnus p. p., D'Orb. 



Cylindrical, somewhat narrowed below, thick-walled, with 

 a wide tubular or funnel-shaped central cavity reaching to 

 the base. On the wall of the stomachal cavity the round 

 ostia of horizontal radial canals, which penetrate deeply into 

 the walls, gradually becoming finer outwards. Surface with 

 scattered smaller ostia connected with horizontal incurrent 

 canals. In well-preserved specimens the lower part of the 

 sponge-body is coated with a siliceous epidermis. 



Skeleton composed of branched corpuscles, in which several 

 smooth arms radiate from a central node ; arms divided at 

 the distal extremity into two or three short branches, running 

 out into root-like fibres. These ends are applied to the similar 

 ends of neighbouring corpuscles, forming cushion-like gnarled 

 knots. As the arms often radiate from the centre at right 

 angles, and their points of union are at nearly equal distances, 

 the skeleton acquires a regular meshed texture, resembling 

 the structure of certain Hexactinellidse. 



This genus is very abundant in the Upper Jura of Swabia 

 and Franconia ; but tlie specimens are usually badly preserved. 

 In the lower beds (White Jura /3 and y) the skeleton is 

 almost always converted into calc spar ; in the Upper White 

 Jura {I, e, and ^), on the contrary, the whole sponge is usually 

 roughly silicified and ill adapted to examination. Good ex- 

 amples have been obtained from Gussenstadt, Sontheim, and 

 Beuren. Only in the Upper Jura. 



1. Scy2'>liia milhporata^ Goldf. iii. 2 ; Quenst. Petr. cxxi. 

 1-7. 



2. Scyphia miUeporacea^ Goldf. xxxiii. 10. 



