50 DK. G. J. HINDE ON CALCISPONGES [Eeb. I9OO, 



6. On some Remarkable Calcisponges from the Eocene Strata of 

 Victoria (Atjstbalia). By George Jennings Hinde, Ph.D., 

 F.R.S., E.G.S.. (Head November 22nd, 1899.) 



[Plates III-V.] 



About two years ago Mr. T. S. Hall, M.A., of the University of 

 Melbourne, forwarded to me, for examination and description, some 

 small specimens of calcisponges which he had collected in different 

 localities in the southern part of the Colony of Victoria. The sponges 

 were found together with numerous species of bivalve mollusca, 

 brachiopoda, fragmentary polyzoa and echinoid-tests, in beds of 

 loose materials, sandy, clayey, and calcareous, which have been 

 regarded, mainly on the evidence of the mollusca, as of Eocene 

 age. The sponges are all fairly perfect as regards outer form, 

 but in the great majority the spicular structure had been much 

 altered in the fossilization, though sufficient Was preserved to lead 

 to the belief that they were new species. In one specimen, however, 

 which came from ' Griffin's Earm ' on the lower reaches of the 

 Moorabool Eiver, north of Geelong, the structure both of the 

 exterior and interior of the sponge was in so unusually favourable 

 a state of preservation that even the smallest spicules could be 

 isolated and examined, and the character of the skeletal mesh could 

 be ascertained with as much precision as in recent sponges. The 

 structural features of this specimen, as will be seen from the 

 description, are distinct from those of any fossil caleisponge 

 hitherto described ; and it resembles, in the peculiar form of the skele- 

 tal spicules and the firmness with which they are welded together to 

 form the mesh, the remarkable caleisponge Petrostroma Schulzei, 

 described recently * by Prof. L. Doderlein, from the Japanese Sea, 

 which has been placed by Dr. Pauff 2 as a distinct order of calci- 

 sponges, the Lithonina, in contrast to all other calcisponges, living 

 and fossil, in which the spicules of the skeleton are regular in form 

 and not fixedly attached together. At my request Prof. Doderlein 

 very kindly supplied me with some fragments of this new sponge, 

 which he has fully described and figured, and I have thus been 

 enabled directly to compare the fossil with the recent representative 

 of the new order. 



In addition to the specimens sent to me by Mr. Hall, I describe 

 here also (pp. 60-61) some very diminutive but perfect examples of 

 calcisponges presented to me by Mr. B. W. Priest, who picked them 

 out of some washings of polyzoa from beds at Mount Martha, 

 Mornington, near Melbourne, which are of the same geological age 

 as those already mentioned. These small sponges, though differing 

 in some details, belong likewise to the same group as the recent 



1 Verhandl. d. Deutsch. Zool. Gresellsck. auf d. 2ten Jabresversammlung 

 (1892) p. 143 ; Zool. Jahrb. vol. x (1898) pp. 15-32 & pis. ii-vi. 



2 Palseontographica, vol. xl (1894) p. 204. 



