798 



W. J. SOLLAS ON THE STRUCTURE AND 



S. acaulis 



Mich. 



Cretaceous. 



Cap la Heve. 



,, arbuscula ... 



>5 



>> 



Environs de Tours. 



„ ficoidea 



>> 



>> 



Poitiers. 



,. Fittoni 



>> 



j » 



Cognac, Loudun. 



„ incrassata ... 



Goldf. 



») 



Nogent le Rotrou, Tours, Rema- 

 lard, Guilbaut,Coulonges. 



„ lagenaria* ... 



Mich. 



Oolitic. 



Caen. 



„ lycoperdoides* 



>> 



Cretaceous. 



Luc, Ranville (Calvados) 



,, midtiocidata 



» 



>i 



Tours. 



„ nuciformis ... 



»> 



>> 



Tours, Honfleur. 



„ pyriformis ... 



Goldf. 



>> 



Rouen, Havre, Tours, Chateau- 

 vieux, St. Aignan, Remalard. 





Mich. 



>> 



Tours. 



(Hallirkoa) 









H. brevicosta 



)> 



>> 



Tours (P. agaric if ormis, Benett, 

 Wilts). 





Lainx. 



>> 



Vaches-noires, Nogent-le-Rotrou, 

 Remalard, Cap la Heve. 





Mich. 



>> 



Vaches-noires, Yillers-sur-Mer. 



1845-46. Eeuss, A. E. < Die Versteinerungen der bohmischen 

 Kreideformation,' vol. ii. p. 72. 



Mention is made of six species, of which four are described as 

 new. 



List of Species. 



8. ternafa, Rss., Lowest Chalk marl, S. foot of Borzen, near Bilin ; Tripelbei'g, 



near Kutschlin. PI. xvii. figs. 1 and 3. 

 S. pt/riformis, Goldf., Upper Chalk marl, Kutschlin. 

 S. elongata, Rss., Upper Chalk marl, Kutschlin, Hundorf, Radowessitz. 



PI. xliii. fig. 1. 

 8. heterostoma, Rss., Lowest hornstone-like conglomerate, S. Borgen, S. Hradisst; 



Lowest Chalk marl, Schilling, near Bilin. PL xvii. figs. 4, 5. 

 8. biseriata, Rss., Conglomerate, southern foot, Borzen. Pi. xvii. fig. 6. 

 8. cervicornis, Goldf., Upper Chalk marl, Kutschlin, Hundorf ; Lower Chalk 



marl, Bilin ; ' Pyropensand ' of Trzibletz. 



S. t temata, the Cnemidium tematum, Rss., of an earlier work 

 (Geogn. Skizz. ii. p. 298), possesses the general structure of a 

 Siphonia, and is in all probability a Lithistid, closely allied to, if 

 not identical with our genus. 



S. elongata. This appears also to be a Lithistid, and is very likely 

 a Siphonia as well. 



S. heterostoma and biseriata. These are both Hexactinellids, with 

 no relations to Siphonia ; on the other hand they closely resemble 

 Stauronema, mihi, in the coarseness of their sexradiate fibre, and 

 in the simplicity of its nodes ; they are like this genus in general 

 form also, and will therefore, I expect, on closer examination be 

 found to be allied to it. 



S. cervicornis is said to be exceedingly similar to the lower part 

 of Jerea arborescens, Mich. 



1850. D'Orbigny, A. ' Prodrome de Paleontologie,' vol. ii. 

 pp. 186 and 285. 

 D'Orbigny includes IlalJ'u-hoa and Choanites with Siphonia, and 



