38 



POST-TERTIARY ENTOMOSTRACA. 



Cytheridea pundillata, Brady. 

 JEucytltere Argus (G. O. Sars). 

 Cytlierura nigrescens (Baird). 



— undata, G. 0. Sars. 



— clatlirata, G. 0. Sars. 

 Cytheropteron latissimim (Norman). 

 Sclerochilus contorfits (Norman). 

 Polycope orbicularis, G. 0. Sars. 



8. Dalmuir, Dumbartonshire. 



The deposit at Dalmuir was first described by Dr. Tliomas Tliompson in a paper 

 entitled " On a deposit of Recent Marine Shells at Dalmuir, Dumbartonshire," and 

 published in the Records of General Science,' vol. i, p. 133 (1835). At that time,, 

 however, the distinction was not drawn between the recent marine shell-beds and the 

 arctic shell-beds, to the latter of which classes the Dalmuir deposit undoubtedly belongs. 

 Dr. Thompson describes the locality as follows : — " The locality in which the fossils are 

 exposed is situated on the banks of the Dalmuir Burn, about 100 yards above the- 

 bridge, by which the road from Glasgow to Dumbarton crosses it, and about a mile 

 from the Clyde. The current of the stream is not very rapid, so that the bed of shells 

 is probably not more than twenty feet above the level of the Clyde, which at that place 

 is sensibly salt at high water. The breadth of the channel of the stream at this place 

 is about fourteen feet, and the depth of the banks is about two and a half feet. The 

 sandy deposit appears to extend on both sides of the stream, upwards and downwards^ 

 without alteration ; but the fossils are confined to a circular or rather elhptical face, the 

 breadth of which (across the stream) is about twenty-five feet, while its length is only 

 about fifteen feet. The deposit extends back from each bank only about six feet, so 

 that more than one half the whole mass has been cut away during the change of the course 



of the rivulet The depth of the bed in its original state must have been twelve 



or fourteen feet." Mr. Sowerby pronounced three of the species there found to differ 

 from any known recent British species. One of them was said to be Natica olaucinoides^ 

 a Crag fossil (really, we believe, N. ajjinis, described as N. clausa by Searles Wood in 

 ' Monograph of Crag Mollusca,' Part I, p. 147) ; another was called Fusus lamellosusy 

 "which had only been observed about the Straits of Magellan" (a mistake for the 

 arctic species now called Troplion clathratum, var. Gunneri) ; and a third, Buccinum 

 striatum, "an unknown species" (now identified with B. Grcenlandicum, Chemnitz). 

 The fact, however, that these species were unknown as British, led Mr. J. Smith to- 



