COEEESPO^'DE^'C£. 



341 



rose to the surface of the water, leaving the shell on the bed of the 

 stream. As the dead bodies floated down the current the heads of 

 islands, masses of fixed drifted wood, and the shores in many places 

 were covered with them, tainting the air with putrid effluvia.' " 



Now, nearly the whole of the shells which occur in this bed of rag- 

 stone appear to have been dead shells. I mean, that from the open 

 state of the valves it is probable that the animals were for the most part 

 dead before they were enveloped in the sand and mud ; and from the 

 large quantity of waterworn (coniferous) wood perforated by litho- 

 domi, that is imbedded with them, it would appear that this stratum 

 had constituted a bank of drifted wood and shells, ^jresenting a very 

 analogous condition to the phenomena above described. Tlie mol- 

 luscous bodies of the trigonias, gervillias, rostellarias, and oysters, 

 etc., detached from their shells, would have been intermingled with 

 drift-wood on such a sandbank ; while, in other cases, the auimal- 

 matter would remain in the shells. These masses becoming fos- 

 silized would present when loose the patches of moUuskite, and when 

 retained in the shells the phosphatic casts observed. 



The liev. J. B. Eeade submitted some of the molluskite to an ana- 

 lysis by Mr. Eigg, who confirmed Dr. Mantell's suspicion of the 

 presence of animal-carbon in it, and states that the darker portion 

 of the substance contains about 35 per cent, of its weight. Dr. 

 Mantell adds that a microscopical examination of some specimens 

 with a low power detects innumerable portions of the nacreous la- 

 minae of shells of extreme thinness, intermingled with carbonaceous 

 matter, together with many siliceous spiculae of sponges, very minute 

 spines of Echinodermata and Polypifera. Of these extraneous 

 bodies he remarks, that probably they became intermingled in the 

 soft animal-mass before the latter had undergone complete decom- 

 position. He proposed the term Molluskite for this fossil sub- 

 stance, and considers the substance of the dark spots and markings 

 iji the Purbeck marble to be identical. Since this paper was read, 

 I have closely examined many of these bodies, and from the presence 

 of minute bones of fishes, I am convinced that a very large proportion 

 are the egesta of fishes. 



{To he continued^ 



COREESPOXDEXCE. 



The Muskham Skull 



Sir, — Have the following facts, stated by an anatomist of European re- 

 putation for tlic last thirty year.^, any bearing on the question of the obli- 

 (piity i\w.fora,ncn 'nnujnum in tlie Muskham skull, as described by Prof. 

 Huxley and Mr. C. Carter Blake, in the ' Geologist' for June last ? 



Speaking of tiic KafRrs, Dr. Knox states (' Eaces of Men,' p. 226), that 

 "the form of the skull differs from om-s, and it is placed dillerently ou 



