46 Reports and Proceedings. 



early period great variation occurred among the Keratosa, which already, at the 

 time of the "Weisse Jura, had evolved such highly symmetrical specialized forms as 

 the Ventriculites ; these, with their contemporary variations, such as Verongioid 

 forms, lived on in great numbers throughout the Mesozoic period, with the close of 

 •which the Ventriculites altogether disappeared ; and the nearest allies dwindled down 

 to the dwarfed and rare genera Verongia, Darivinella, and perhaps Spongionella. 



Discussion. — Mr. J. F. Walker was not prepared to admit that all phosphatic 

 nodules had been organized bedies, inasmuch as most of the fossil shells in the deposit 

 •were found filled with phosphatic mud of the same nature as the nodules. 



Mr. Charlesworth also disputed the organic origin of the amorphous coprolites, 

 and pointed out the analogies between the so-called coprolites of the Crag and those 

 of the Upper Greensand, and the flints of the Chalk. He cited Ehrenberg as of 

 opinion that the latter were masses of fossilized Infusoria, while Dr. Bowerbank 

 maintained that they were merely fossil sponges, and drew the deduction that caution 

 was necessary in accepting any theory as to the origin of the phosphatic nodules. 



Mr. Seeley was not entirely in accord with Mr. Fisher as to the number of forms 

 assumed by the phosphatic nodules. There were some that resembled common 

 septaria, and in many cases the original form, especially in the case of the presumed 

 ventriculites, had been much modified by rolling on the sea-bottom. In support of 

 the view of the sponge-origin of some of the nodules, he exhibited some of the 

 modern forms of sponges enveloping different objects in the same manner as the 

 phosphatic matter included in shells and other fossils. The Porospongim in the Wood- 

 wardian Museum were, he said, not phosphatic, but calcareous fossils; and he 

 thought there had been some mistake by Mr. Sollas in alluding to these specimens. 

 The phosphatic masses were frequently drilled and filled with glauconite and other 

 matter. He doubted the ventriculite origin of many of the nodules, and pointed out 

 that the so-called ventriculites were in reality OcellaricB. 



Mr. H. Woodward mentioned that a similar structure to that described in the 

 Ventriculites had been observed by his colleague Mr. Kent in a modern siliceous 

 sponge, and observed on the similarity in some respects between ventriculite-structure 

 and that of Euplectella aspergillum. He thought that, whatever might be the origin 

 of some of the Chalk-flints and phosphatic nodules, it was quite impossible to 

 refer the whole of them to the growth of sponges. 



Mr. Fisher, in reply, did not agree with some of the speakers in considering that 

 various organic remains were often found imbedded in coprolitic matter, though many 

 were filled or partially covered with it. There was, he thought, a diff'erence between 

 the coprolites of the Crag and those of the Greensand ; the surface of the great bulk 

 of the latter had to his eye an unmistakably organic appearance. In some cases he 

 thought they might have been allied to Alcyonaria. He did not agree with Mr. 

 Seeley as to many of them being in a rolled condition. 



Mr. Sollas stated that some of the coprolites contained siliceous Xanthidia and 

 Polycystina uninjured, which afl'orded an argument against regarding the Ventriculites 

 as having originally had a siliceous skeleton, which had subsequently been replaced 

 by phosphate of lime. He had also found well-preserved siliceous spicules in the 

 coprolites. The forms, though numerous, were well defined and susceptible of classi- 

 fication, which he had attempted to undertake. He could not acknowledge any 

 mistake in reference to Porospongia. 



Geologists' Association. — December 6th. — The Eev. Thos. Wiltshire, M.A., 

 F.G.S., in the Chair. 



1. " On Coal Seams in the Permian at Ifton, Shropshire, with Remarks on the 

 supposed Glacial Climate of the Permian Period." By D. C. Davies, F.G.S. The 

 author showed the existence of three well-defined and workable seams of coal above 

 the red sandstones and marls which are generally held to form the base of the 

 Permian strata. He then proceeded to show the identity of these red beds with 

 similar beds overlying the Coal throughout several of the Midland Counties, and 

 with the red sandstones of the north of England, and also that the overlying sand- 

 stones, shales, and coals were the equivalents of the magnesian limestones and 

 calcareous conglomerates which occupy the same horizon in widely distant places. 

 After referring to the former probable extension of these beds over a large area, the 

 author pointed out that in the neighbourhood described the gap or break, which is 

 usually supposed to occur between the Coal-measures and the Permian, was partly, if 

 not quite, bridged over. He also noticed how the difiFerent geological formations 

 were dovetailed into each other, the old passing into the new, and not divided by 



