Mr Smith on the Changes of the Level of the Sea, 379 



My attention was first called to the subject by the discovery 

 of marine shells, agreeing in general with those of the adjoin- 

 ing seas, embedded in blue clay, at Ardincaple, the seat of 

 Lord John Campbell, in Dumbartonshire. At that time it was 

 usual to ascribe all such appearances to diluvial action ; and 

 although the shells bore no marks of violent transportation, the 

 bivalves being entire, with the epidermis uninjured, and in their 

 natural position ; yet, as the distance from the sea was small, I 

 imagined they might have been protected from injury by having 

 been lodged in an eddy. Two of the shells appeared to differ 

 from any known species; one of them, a Tellina {T. approxi- 

 ma)y is so common, as in many localities to become character- 

 istic of this deposit. It resembles the T. tenuis, but is dis- 

 tinguished by a brown epidermis. The other resembled a Na- 

 tica, but was destitute of the umbilicus. The only specimen 

 procured of this shell I unfortunately broke, but not until a 

 sketch of it had been taken.* Lord John Campbell was kind 

 enough to order a new excavation to be made, in hopes of 

 finding other specimens, but without success. 



Soon after this, Mr Thomas Thomson gave an interesting 

 description of a similar deposit at Dalmuir in Dumbartonshire, 

 in the Records of General Science.t He collected twenty-nine 

 species, which were submitted to the inspection of Mr Sowerby , 

 who pronounced three of them to differ from any known recent 

 British shells ; one of them was said to be Natica glaucinoides, 

 a crag fossil ; another, Fusus lamellosus, which had only been 

 observed about the Straits of Magellan ; and a third, Bucci- 

 num striatum, an unknown species. This remarkable fact, 

 coupled with my own observations, led me to imagine that the 

 term " recent,"" which had usually been applied to such depo- 

 sits, was perhaps not rigic^ correct. In order to ascertain how 

 far it was so, I determined to collect as many of the shells be- 

 longing to them as I could. In a fresh excavation I made at 

 Dalmuir, I increased the number of species, from that locality 

 alone, to upwards of seventy. The Rev. Mr Landsborough 

 of Stevenston, in Ayrshire, was kind enough, at my request, 

 to collect marine remains from the elevated shelly deposits in 



• Plate XLV. Fig. 18. t Vol. i. p. 131. 



