4.2 BRITISH FOSSIL SPONGES. 



Schweigger. Fossil calcisponges do not appear to be even named, and 

 Stromatopora is still retained in the Sponges. 



225. 1885 Sollas, W. J. On the Physical Characters of Calcareous and Siliceous 



Sponge-spicules and other Structures {Scientific Proc. Royal Dublin 



Soc, n. s., vol. 4, pp. 374—392, PI. XV). 

 Describes methods for determining the refractive-index and specific gravity 

 of spicules of siliceous and calcareous sponges ; treats also of the optic axis 

 and angles of extinction, and of the effects of etching of calcisponge spicules. 

 States that the Pharetrones must now be relegated to the Calcispongiee ; but 

 Pharetrospongia is certainly a siliceous Sponge. Many spicules of calcisponges 

 are shown to be elliptical in transverse section. 



226. 1885 Sollas, W. J. On an Hexactinellid Sponge from the G-ault, and a 



Lithistid from the Lias of England {Scientific Proc. Royal Dublin Soc. y 

 vol. 4, pp. 443—446, PL XXI). 

 Describes as new species Platychonia Brodiei and Craticularia calathus. 

 Figures are given of their form and structures. 



227. 1885 Sollas, W. J. On Vetulina stalactites, 0. Schmidt, and the Skeleton of 



the Anomocladina (Proc. Roy. Ir. Acad., S. 2, vol. iv, pp. 486 — 492, 

 Pis. Ill, IV). 

 Shows that the elementary spicules of this recent species consist, as 

 0. Schmidt described them, of central nodes from which a variable number of 

 rays extend, and concludes that the spicules of Astylospongia and other fossil 

 Anomocladina are of a similar character. The views of Zittel that the 

 elementary spicules of this family are simple rodlike spicules with branching 

 extremities are thus shown to be untenable. Gives a fresh definition of the 

 family Anomocladina, similar to that first proposed by Zittel in the ' Studien.' 



228. 1885 Pocta, P. Ueber zwei neue Spongien aus der bohmischen Kreideforma- 



tion (Sitzungsb. d. Jc. bohm. Gesell. der. Wiss. sep.copy, pp. 1 — 7, PI. 1). 

 Describes and figures as two new species Casearia cretacea and Verrucoccelia 

 uvaformis. 



229. 1885 Kaiser, E. Lodanella mira, eine unterdevonische Spongie {Zeitsch. d. 



deutsch. geol. Gesell, pp. 207—211, PL XIV). 

 The form thus named consists of the negative casts of a funnel-shaped 

 body whose walls were penetrated by anastomosing canals. No structure 

 whatever has been preserved, and the character of the organism cannot 

 therefore be determined. 



