Mr. H. T. Carter on the Stromatoporidse. 321 



lished (Ann. 1877, vol. xix. p. bb et seq.), as well as those given 

 in this paper. The coenenchyma of Parkeria I hold to have 

 been calcareous, and therefore the presence in it of all siliceous 

 material to have been subsidiary or foreign, as in Stromatojiora^ 

 to say nothing of the hosts of microscopic foreign organisms 

 that were enclosed within their structures respectively during 

 growth. 



Still the " Flamborough-Chalk Fossils " to which I have 

 alluded (Ann. 1878, vol. i. pp. 413-415), I now hnoio not to 

 have been the coralla of Hydrozoa as then suspected, but to 

 have been the skeletal structures of Lithistid sponges respec- 

 tively, which Prof. Zittel told me he had found at Ahlten, in 

 Hanover, so much better preserved that the spiculation in them 

 was undeniably Lithistid. They had been called by Phillips 

 " S2)ongia " generically, with appropriate specific names, and 

 figured in his ' Geology of Yorkshire.' But by far the most 

 beauti ful representations were drawn and lithographed, under the 

 direction of Mr. Ed. Charleswortli, for his London Geol. Journal 

 under the name of Rhizosj^ongia polymorpha. These, unfortu- 

 nately, were never published; but Mr. Charlesworth, in kindly 

 presenting me with a set of them a short time since, added 

 that he had written an account of the fossil Sponges of the 

 Yorkshire Chalk, which might be found in the Proceedings of 

 the Yorkshire Phil. Soc. for 1855 (vol. i. p. 73, pi. 1), with 

 one illustration. In the British Museum these fossils now 

 appear under the generic name of Eudea^ Romer. 



I would also mention here that Prof. Zittel has kindly sent 

 me some calcareous fossils, with microscopic specimens of their 

 structures respectively, showing that they were composed of 

 fibre charged with such characteristic triradiate spicules that 

 I must now admit that heretofore there have been calcareous 

 sponges which have become fossil, although, as Prof. Zittel 

 will probably show in his forthcoming paper on them, they 

 were of a different kind from any now living. 



To return, however, to Messrs. Nicholson and Murie's de- 

 lightful exposition of the Stromatoporida3, it is pleasant to me, 

 living close to the great focus of Devonian 8tromato])orcB^ to 

 find, in the footnote at p. 230, the evidence of an eye-witness 

 that " the Stromatoporoids of the Eifel limestone are in no 

 respect fundamentally different from those of the Devonian 

 of Devonshire and North America." 



Lastly, the authors repeat their opinion that, under the cir- 

 cumstances, the Stromatoporidfe should be viewed as " a new 

 section of the Calcareous Sponges, for which " they " propose 

 the name of Stromatoporoideay 



But, considering that our conception of a sponge will not 

 Ann. & Mag. N. Hist. Ser. 5. Vol. n. 22 



