ANNIVERSARY ADDRESS OF THE PRESIDENT. CXXxix 



The fossils are supposed to have been of Devonian age, and Mr. 

 Woodward explains the manner in which the mud surrounding the 

 shell had entered into some of the chambers, in which the siphuncle 

 was incomplete ; how water, charged with carbonate of lime in solu- 

 tion, had filtrated into others, either lining them with a calcareous 

 tufa, or filling them with a crystalline limestone ; and that in others, 

 the calcareous lining not having been complete, the mud, on the dis- 

 solution of the external shell, had penetrated and filled up the 

 vacuity. Mr. Woodward also pointed out certain appearances tend- 

 ing to show a gradual separation and collapse of the lining mem- 

 brane of the air-chambers towards the apex during the lifetime of 

 the animal ; and concluded with some remarks on the structure and 

 filling up of the siphuncle in Actinoceras and other allied forms of 

 Cephalopoda. Doubtless these ingenious remarks of Mr. Woodward 

 will recall to the mind of many, the former labours, and particularly 

 the verbal expositions, of the late Charles Stokes, who devoted so 

 much of his attention to the elucidation of the Orthocerata. 



Mr. Binney brought under the notice of the Society the supposed 

 foot-prints in the millstone-grit of Tintwistle, Cheshire. The 

 impressions are five in number, the two longest measuring 13 

 inches in length at the bottom, and 17 inches at the top, with a 

 breadth of 4 and 3| inches at the bottom, and 8 and 9 inches above, 

 and a depth of 3 inches. The distance between the impressions is 

 2' 10"yj and there is some little difference in shape, arising appa- 

 rently from the accidental casualties of an animal moving on wet sand. 

 Supposing the impressions to have been made by the same kind of 

 animal which produced those on the Permian sandstone of Corn- 

 cockle, though they are much larger than those of Chelichnus Titan 

 of Jardine, Mr. Binney proposes the name of C. ingens. 



Mr. Rupert Jones, in a very interesting appendix to a paper by 

 the Rev. P. B. Brodie, on the Upper Keuper Sandstone of Warwick- 

 shire, makes a very important rectification of fossil organic nomen- 

 clature, by showing that some of the minute species of Posidonomya 

 should be removed from the Molluscs, and classed with the bivalved 

 phyllopodous Crustacea (Entomostt-aca), their nearest analogue being 

 found in the genus Estheria of Riippell and Baird. The great abun- 

 dance of individuals in the species which has given rise to these ob- 

 servations, the Posidonomya minuta, or Estheria minuta of Jones, in 

 the Trias of Europe, renders it characteristic of the deposits of that 

 geological epoch, and an index therefore to their occurrence in other 

 countries. With this view of the importance of the fossil, and taking 

 into account the association, in some cases, of labyrinthodont and 

 other reptilian forms with this Estheria, and in others that of the 

 Estheria with sandstones and shales connected with the flora of cer- 

 tain epochs, Mr. Jones justly observes that it may be used in deter- 

 mining in some doubtful cases, such as those of Central India, and of 

 Virginia, whether the deposits ought to be classed with the Triassic 

 or with the Jurassic, or be considered a transition-group between them. 

 The recent Estheria is marine ; but, as closely- allied forms are of 

 freshwater habits, and as some species of the same genus are marine. 



