X Proceedings. {Deceinber ijth, igio. 



University College, London, ^^ by R. AV. Chambers (8vo., Oxford, 

 1910), presented by the University College Library, London. 



Mr. Philip Kemp, M.Sc.Tech., showed experimentally 

 that pure rubber strip which had not been previously extended 

 expanded on the application to it of heat, whereas rubber, which 

 liad previously been stretched, on being warmed contracted 

 slightly before it began to expand. 



Mr. G. P. Varlev, M.Sc. (Vict.), exhibited a specimen of 

 Pavonazzo marble from Carrara containing black veins, which, on 

 examination, were found to be crystallised hematite, and not 

 graphite as was supposed. 



Miss Margaret C. March, K.Sc, read a paper, com- 

 municated by Dr. G. Hickling, entitled, "A Preliminary 

 Note on the Effect of Environment on Unio pictorum, 

 U. iu)? I idles, and Anodonta cygnea." 



The paper will be printed in the Memoirs. 



Mr. D. M. S. Wat.son, M.Sc, read a paper entitled " Notes 

 on some British Mesozoic Crocodiles." 



The paper will be printed in the Memoirs. 



Professor F. E. Weiss, D.Sc, F. L.S., communicated a note 

 " On Sigillaria and Stigmariopsis." The author exhibited 

 some specimens of axes of Sigillaria associated with Stigmarian 

 bark. From the repeated occurrence of these specimens it was 

 suggested that they represented the base of the aerial or the 

 subterranean axes of Sigillaria, probably of the Eusigillaria type. 



The secondary wood was more copiously developed than is 

 general in the aerial axes. The primary wood was of Sigillarian 

 type, so that these Stigmarian axes have centripetal i)rimary 

 wood, and their pithcasts would be striated like those described 

 for Stigmariopsis. 



It was noticed that in some instances small axes were found 

 in contiguity, and apparently in continuity, with the main axes. 

 These smaller axes resemble the ordinary Stigmarian axes vei) 

 nearly, and do not show the centripetal primary wood of the main 

 axis, but only a few fine tracheids in the pith region. 



