/ 



252 Rev. D. Landsborough's Account of a I>redgmg Excursion. 



Though the excursion proved a very dehghtful one, the weather 

 and the scenery being charming, it was not very productive ; it was 

 at first too calm for di'edging, and latterly it became rather too 

 rough for the purpose. Bvit di'edging was not our only object. 

 Mr. Smith is well-known in the scientific world from what he has 

 done for geology, especially for a branch of it which bears on " the 

 last changes in the relative levels of the land and sea in the British 

 Islands." In cariying on his researches he saw that it was of im- 

 portance to make a catalogue of the recent shells found at present 

 in our seas, as well as a catalogue of those that are found in our 

 most recent deposits, that they might be compared with each other. 

 At the outset he thought that all these comparatively recent de- 

 posits were of the same age ; but he has been led to conclude that 

 there are recent, and more recent deposits. The older of these 

 he calls by the usual name, the newer Pliocene, as it contains a 

 few shells not found at present in our seas. The other he calls 

 post-tertiary ; for though it contains no shell that is not at pre- 

 sent found in the adjoining sea, it has e\ddently been deposited 

 when the sea was on a higher level. I concm* with him in the 

 propriety of this distinction. His lists of recent, newer pliocene, 

 and post-tertiary shells are now long, and I have had the plea- 

 sure of adding to all the three lists. 



But let us begin with the sea. On the 13th of last August 

 we shot our di'edge in the bay of Rothesay, and were in high 

 expectation of a rich haul, when, lo ! all that was brought up was 

 a heather besom. Still everything from the deep sea should be 

 regarded with a keen eye. I scrutinized it branch by branch ; 

 but all that I could discover were some small specimens of Pecten 

 opercularis and of Galathea squamifera. 



From Rothesay we sailed up the Kyles, and had one haul of 

 the dredge before we came to anchor near to Ru-bodach. It was 

 not very productive. There were hundi'cds of pretty Ophiurce, 

 O. texturata, 0. albida, 0. rosularis, 0. gramdata, O. beUis ; but 

 as there seemed to be nothing rare among them they were re- 

 turned to the deep. Tliere were some good specimens of Emar- 

 ginula fissura ; and two examples of a rare and beautiful Trochus, 

 found for the first time in this country some dozen years ago by 

 Major INIartin on the Stevenston strand. As it was thought to 

 be a new species it was called Trochus Martini, but it has since 

 been ascertained that it is Trochus millegranus of Philippi. 



We afterwards rowed to shore in the boat, and landed near 

 Balnacoolie, where Mr. Smith and Mr. Sowerby some years ago 

 had discovered a rich newer pliocene deposit. We had not been 

 long ashore until we found two or thi'ee specimens of Panopcea 

 Bivona', a rare subfossil shell which we were chiefly in search of, 

 as it had been found for the first time in Scotland by Mr. Smith 



