President's Address. 367 



rocks of Girvan. From the Lower Carboniferous rocks she 

 makes fourteen new species of Murchisonia (proper), ten new 

 species of the genus Aclisina, de Koninck, and makes a new 

 genus Ehabdospira, with one species. In addition to fossils 

 gathered by herself, she has taken advantage of the collec- 

 tions of Mrs Gray, Professor Lapworth, John Smith, the late 

 James Bennie, E. Neilson, the late Dr Hunter-Selkirk, the 

 late J. Thomson, Prof. J. Young, the late Dr J. Young, and 

 also that of the Geological Survey. 



A comparison of Mrs Gray's list of Silurian Fossils from 

 Girvan^ shows that the species of Gasteropods numbers 50, 

 while the number given by Etheridge in his address is 28.^ 

 This addition is greatly due to the publication in 1881 of the 

 late Professor G. Lindstrom's " Monograph on the Silurian 

 Gasteropods and Pteropods of Gothland," ^ which has allowed 

 Mrs Gray to determine many of the fossils in her collection. 

 This splendid monograph is certain to have a considerable 

 influence in the determination and classification of the 

 Gasteropods of our Scottish rocks. 



During the progress of the Geological Survey in Durness 

 and Skye, a considerable number of Gasteropod remains 

 were collected from the Durness Limestone, in addition to 

 those enumerated in Mr Etheridge's address, who only 

 records eight species.* More than that number of species 

 of the genus Murchisonia alone occur in the collection, and 

 several American forms of the peculiar genera Maclurea 

 and Ophileta are represented.^ 



PTEROPODA. 



There is a growing feeling amongst palaeontologists that 

 the Palaeozoic fossils that have been classed with the Ptero- 

 poda do not really belong to that order. As yet, no- true 

 Pteropod remains have been obtained from strata older 

 than the Cretaceous. There is therefore great difficulty in 



^Mem. Geol. Sur., "The Sil. Rocks of Brit.," vol. i. pp. 686-697, 1900. 



2 Proc. Roy. Phys. Soc. Edin., vol. vii. p. 27, 1881. 



^ Kon. Svenska. Vetensk. Akad, Harull., Bd. xxx., 1881. 



* Proc. Boy. Phys. Soc. Edin., vol. vii. p. 27, 1881. 



^ Mem. Geol. Sur., "Summary of Progress for 1898," p. 55, 1899. 



