CEROSPONGIA, 331 



of Scotland, a genus, Acanihospongia, closely allied to Hyalonema, has been described by Professor 

 Young, of Glasgow, and later by Mr. Carter. In the Jurassic strata Hexactinellids are well 

 represented, and in the Chalk they abound, the graceful and varied Ventriculites being well known 

 to collectors in the Downs of Sussex, 



CEROSPONGIA. 



This order consists of Sponges with a spongin skeleton, but without proper spicules. The 

 axis of the spongin fibre may be occupied by soft organic matter only (Ceratina), or it may involve 

 various foreign bodies (Psammonemata) [Greek, psammos, sand]. The Bath Sponge, already fully 

 described, is a member of the Psammonemata. Luffaria, of which an illustration is given in Plate 

 71, belongs to the Ceratina. No examples of these widely-distributed sponges are yet known in th? 

 fossil state. 



The literature of the Sponges is copious, but much of it very inconveniently scattered La 

 separate memoirs through journals and magazines. For general information, and descriptions of 

 species, may be quoted Oscar Schmidt's volumes on the Sponges of the Coast of Algiers, of the 

 Atlantic Ocean, and of the Gulf of Mexico ; Haeckel, Die Kalkschwamme ; numerous papers by 

 Carter in the " Annals and Magazine of Natural History," where also papers by Sollas appear; 

 for masterly accounts of structure and embryology see F. E. Schulze in several numbers of the 

 "Zeitschrift fur Wissenschaftliche Zoologie," where also are papers by Metschnikoff and Oscar 

 Schmidt. A history of the Sponges will be found in George Johnston's " British Sponges," and good 

 descriptions of British species in Bowerbank's " Monograph on the British Sponges," 8 vols. Jules 

 Barrois has published "Researches on the Embryology." For fossil Sponges see the fine works 

 of Zittelj and papers by Sollas in the Quarterly Journal of the Geological Society. 



W. J. SOLLAS. 



