M. K. A. Zittel on Fossil LitMstidce. 391 



1. Carterella cylindrica, Zitt. 



(^=Jerea arborescenSf cylindrica, and elongata, Giimb. Ostb. Grenzgeb. 

 p. 761.) 



Very long, cylindrical, simple, rarely dichotomous above, 

 laterally somewhat compressed, with a long, simple, strongly 

 fm-rowed root ; vertex rounded. Surface coarsely reticulated, 

 with numerous straight horizontal canals, which give the 

 transverse section a radiate appearance. Whole sponge 

 traversed by several vertical tubes, and composed of coarse, 

 smooth, curved, filiform spicules, which rarely show a ten- 

 dency to fork. Greensand of Kelheim and Regensburg ; very 

 abundant. 



*2. Jerea spicidigera, E,om. Spong. xii. 6 ; Quenst. Petr. 

 exxxv. 1, 2. Cuvieri-^lQMQx and Mucronatus-c\vA\^. 



?3. Eulespongia^ sp., Quenst. ib. cxxxv. 1, 2. Cavieri- 

 Planer. 



Heterostinia, Zitt. 



Cup-shaped, usually stalked, with a branched root. Both 

 surfaces with the scattered impressed ostia of radial canals. 

 Vertical canals in the stalk. Skeleton of two kinds of ele- 

 ments of different sizes. The smaller, which form the prin- 

 cipal mass, are strongly bent, much-branched, and filigreed 

 all over ; the larger ones smooth, branched, with attenuated 

 and pointed ends. 



The only known species, Heterostinia cyathiformis^ Zitt., 

 is from the Senonian of E,ouen. In external form it agrees 

 perfectly with the figures of Glienendopora suhplena and 

 ohliqua, Mich. Ic. xli. 1, 2; and it is probable that one of 

 these is identical with the present species. Numerous speci- 

 mens are in the Museum of Geneva. 



ISORHAPHINIA, Zitt. 



SipJionoccelia p. p., Rom. 

 Eidespongia p. p., Queust. 



Cylindrical, simple, narrowed below, stalked, truncate above; 

 wall of moderate thickness, central cavity wide, tubular. Sur- 

 face smooth, without large ostia. The whole sponge-body 

 composed of very large, slightly curved, cylindrical spicules, 

 thickened, but rarely dichotomous at the ends, with a wide 

 and long axial canal. In the interior of the wall these 

 spicules are united in bundles, their somewhat bent extremities 

 being at regular distances interlocked so as to form knots, 

 in each of which several radiating bundles of spicules unite 



