28 Proceedings of the Royal Physical Society. 



Univalves, . . . . 28 species. 

 Pteropoda, .... 6 „ 



Cephalopoda, . . . . 11 „ 



In concluding this portion of my remarks, it only remains to 

 refer again to the Upper Silurian beds of the Kirkcudbright 

 district. The last reference made to them was in connection 

 with Professor M'Coy's determination of fossils collected 

 for Professor Sedgwick. In 1851 Professor Harkness noticed 

 the occurrence of Ortlioceratites in the flagstones of Balmae, 

 in a paper "On the Silurian Eocks of Dumfriesshire and 

 Kirkcudbrightshire."* Three species were found by Hark- 

 ness — Orthoceras SedyivicMi (Forbes), 0. anmdatum (Sby.), 

 and 0. tenuicinctum (Portlock). Nothing further has been 

 published of any note on fossils of these beds so far as I am 

 aware, but in September 1874 Mr James Bennie made a 

 large collection of organic remains, which, it is to be hoped, 

 will be described some day. One of the most noticeable is a 

 large Orthoceras, commonly met with in pieces and fragments. 

 Entire specimens sometimes occur, and these show the 

 character and arrangement of the numerous close septa 

 exceedingly well. In the many pieces of fragments found 

 the convex surfaces of the chambers show very peculiar and 

 interesting groovings and markings, which would well repay 

 detailed study. 



Such, Gentlemen, is a brief and very incomplete history of 

 Silurian Conchology in Scotland. It is yet, comparatively 

 speaking, an open and unexplored field, and much remains to 

 be done in the systematic description of the shells from the 

 Silurian deposits of the Pentland Hills, the K-W. Highlands, 

 Girvan, and Kirkcudbrightshire. 



CONCHOLOGY OF THE OLD RED SANDSTONE OF SCOTLAND. 



" In the ichthyolite beds of Cromarty and lioss, of Moray, 

 Banff, Perth, Forfar, Fife, and Berwickshire, not a single shell 

 has yet been found ; but there have been discovered of late, 

 in the upper beds of the Lower Old Eed Sandstone in 



* Quart. Jour. Guol. Sue, vii., pj). 46-65. 



