BIBLIOGRAPHY. 27 



145. 1877 Zittel, K. A. Studies on Fossil Sponges, I, Hexactinellida (Annals 



and Mag. Nat. Hist., 4 S., vol. xx, pp. 257—273, 405—424, 

 501—517). 

 Translated by W. S. Dallas from the " Studien " in ' Abliand. d. k. bayer. 

 Akad. der Wiss.,' II CL, Bd. XIII. 



146. 1877 Zittel, K. A. Untersuchungen uber fossile Spongien (Neues Jahrbuch, 



pp. 705—709). 

 A short notice and criticism of the first part of vol. v of 'Quenstedt's 

 Petrefaktenkunde.' 



147. 1877 Sollas, W. J. On Pharetrospongia Strahani, a fossil Holorhaphidote 



Sponge from the Cambridge Coprolite Bed (Quart. Journ. Geol. Soc, 



vol. xxxiii, pp. 242—255, PI. xi). 

 Gives a minute description of its structural characters ; it is composed of 

 anastomosing fibres, which consist of minute acerate spicules, closely arranged, 

 generally parallel to one another. The forms are now nearly entirely cal- 

 careous, but in some cases a thin external film of the fibre with some of the 

 spicules is siliceous. The Sponge is regarded as having originally been 

 siliceous, and it is placed in the family Benierida. 



148. 1877. Sollas, W. J. Ou the Structure and Affinities of the genus Siphonia 



(Quart Journ. Geol. Soc, pp. 790 — 835, Pis. xxv, xxvi). 

 The minute structure of the skeleton is fully described ; it is stated to 

 consist of quadriradiate spicules with four diverging arms, bifurcating near 

 their extremities and terminating in a number of rounded apophyses with 

 intervening concavities. This structure is compared with that of the existing 

 lithistid Discodermia. Details are given of the mineral changes produced by 

 fossilization, including that of the replacement of the original silica by calcic 

 carbonate, which had been already noted by Pomel and Zittel. Siphonia is 

 placed in the family Pachastr ell idee and the order Holorhaphidota, Carter. 



149. 1877 Sollas, W. J. On Stauronema, a new genus of Fossil Hexactinellid 



Sponges, with a description of its two species 8. Garteri and 8. lobata 

 (Ann. and Mag. Nat. Hist., S. 4, vol. xix, pp. 1 — 25, Pis. I — V). 

 Describes a fan-shaped Sponge with a very robust spicular mesh, the canals 

 in which are stated to pass ordinarily from one node to another, and thus to 

 differ from recent hexactinellids. The wall of the Sponge forms a thin, so- 

 called oscular plate, which is overgrown at its base by a thick mass of irregu- 

 lar spicular tissue. 



