366 Proceedings of the Royal Physical Society. 



jun. Since his departure for Australia, the work has been 

 taken up by Dr Wheelton Hind, who, in the preparation of 

 his monographs on the Carboniferous Lamellibranchs, has 

 largely used the material of the magnificent collections of 

 Mr Neilson and other Glasgow geologists, as well as that 

 of the Geological Survey.^ 



During the progress of the Geological Survey from 1883 

 to 1885, and again in 1898, a considerable number of bivalves 

 were obtained from the Durness Limestone, which is of 

 Upper Cambrian age. These belong to the genus Mtchasma,^ 

 Billings, U. Blumenhachii being the only species, and hitherto 

 only known to occur in Newfoundland and Canada. The 

 Scottish specimens evidently belong to several species, and 

 there are several forms which seem to connect the genus 

 with the genus Uopteria of Billings.^ The genus Euchasma 

 is placed by Dr William Dale among the Cardiolidse.* In 

 Etheridge's address above mentioned he enumerates 12 

 species of Lamellibranchs^ from the Silurian rocks of Girvan, 

 while Mrs Gray's list shows 26 species from the same rocks.*^ 



GASTEROPODA. 



The chief work among Scottish Palaeozoic Gasteropods has 

 been done by Miss Jane Donald, and published in a series of 

 papers in the Quarterly Journal of the Geological Society from 

 1887 to 1898.'^ In these papers she deals chiefly with the 

 genus Murchisonia, d'Arch. et de Vern., dividing it up into 

 several subsections. She makes a new species and two 

 varieties of the subgenus Ectomaria, adds two new species 

 to Horrtiotoma from the Durness Limestone and the Silurian 



^ "Mon. on Carbonicola, Authracomya, and Naiadites," Palceontogr. Soc.^ 

 pt. i., 1894 ; pt. ii., 1895 ; pt. iii., 1896. "Mon. on Carboniferous Lamel- 

 libranchiata, " Palceontogr. Soc, pt. i., 1896 ; pt. ii., 1897; pt. iii., 1898. 



2 Cancul. Palceoz. Foss., vol. i. p. 360, 1861-1865. 



3 Ganad. Palceoz. Foss., vol. i. p. 221, 1861-1865. 



^ Eastman's translation of "Zittel's Palseontology," p. 85, 1898. 

 ■' Proc. Roy. Phys. Soc. Fdin., vol, vii. p. 27, 1881. 



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

 '' Quart. Jour. Oeol. Soc, vol. xlv. pp. 620-656, 1899 ; vol. xlviii. pp. 562- 

 575, 1892; vol. liv. pp. 4-72 and 251-272, 1898. 



