470 M. K. A. Zittel on Fossil Lithistidoe. 



*1. Siphonoccelia sulcifera^ Rom. Spong. xi. 7. From the 

 Upper Cretaceous of Linden, Ahlten, and Dolberg, near 

 Hamra. 



Callopegma, Zitt. 



Cupulospongia p. p., auct. 



Sponge basin- or funnel-sliaped, sessile or short-stalked, 

 thick-walled ; outer surface with round pores ; inner surface 

 in the centre sometimes with larger oscula, from which verti- 

 cal canals penetrate into the sponge. Skeleton coarsely 

 meshed, loose, composed of lai-ge, rather regular quadri- 

 radiates witli smooth arms, the ends of which are strongly 

 branched (PL VIII. fig. 1 ) ; the short canals of the four arms 

 meeting in the middle. Surface, in well-preserved specimens, 

 coated with forked anchors, their long shaft turned inwards. 

 Also numerous bacillar spicules of different forms and sizes, 

 and a few small anchors with recurved simple prongs. 



Two species from the Upper Cretaceous of North Germany 

 and Belgium. 



1. Callo2oegma acaule^ Zitt. Basin-shaped to hemispheri- 

 cal, either free or attached by a short wart-like stalk. Very 

 thick-w^alled ; in the bottom of the depressed upper surface 

 several large round oscula. Outer wall porous. Under 

 surface with some tubercles. Ahlten, Linden, Ciply. 



2. Calhpegma Schlo ulacki ^ Ziii. Basin- or funnel-shaped; 

 central cavity very wide and deep ; attached by a broad base. 

 Muc7'07iaf US-chalk, Ahlten. 



Trachysycon, Zitt. 



Plocoscyphia p. p., Rom. 

 Sporocalpia p.p., Poniel. 



Sponge from ficoid to elongate- ovate, stalked, with a tubu- 

 lar central cavity, on the wall of which are the ostia of the 

 rather coarse radial canals. Surface with conical pointed 

 warts, from the apices of which fine furrows radiate. Stalk 

 and lower part of the sponge-body smooth, furnished only 

 with pore-like ostia, sometimes coated with a wrinkled sili- 

 ceous membrane. Corpuscles large, irregularly quadriradiate. 

 The four thick arms short and smooth, divided at the ends 

 into several knotty branchlets. 



1. Trachysycon {FlocoscyjpMd) muricatum, Hom. Spong. 

 p. 20, X. 9. From the Quadratus-chsWi of the Sutmerberg. 

 Pomel refers to it under the name of SporocoJina; but in this 

 genus are united a true Hexactinellid {Plocoscyphia morchella, 

 Rom.) and the present Lithistid. 



