SHELLS ABOVE THE PilESEXT LEVEL OE THE SEA. 355 



Eleven of the species of 3Iollusca in the above list arc arctic or 

 northern, viz. Leda perniila, Astarie compressa, A. horealis, A. ere- 

 nata, TeUina calcaria, Saxicava norvegica, Natica affinis^ Tricliotropis 

 horealis, Troplion clafhratus (typical), T. latericeus, and Pleurotoma 

 pyramklaVis ', the first, third, fourth, fifth, seventh, and three last 

 are Norwegian and not British. These species represent a depth 

 of from ten to twenty fathoms. The other species are littoral, 

 or inhabit shallow water ; and I believe they still live in Carnarvon 

 Bay. All the organisms are more or less fragmentary, perhaps 

 owing to glacial action. They are all together 63 ; but that number 

 might be considerably increased by future observers. 



DlSCTJSSIOI^. 



The President pointed out that one great value of this paper 

 consisted in its giving a complete list of the very fragmentary 

 forms found in the Moel-Tryfan beds. 



Mr. W. W. Smtth said that fossils had not been found in any of 

 the superficial deposits on the flanks of Moel Tryfan ; the hill 

 has been rendered easily accessible by a narrow-gauge railway. 



Prof. T. M'K. Hughes asked the author if he distinguished 

 between those deposits in which the shells appeared not to have 

 drifted far from their habitat and those in which, as in the case of 

 Moel Tryfan, they were evidently the dead shells thrown up on a 

 shingly shore. He drew attention to the fact that the flints &c. in 

 the Moel-Tryfan beds, apparently derived from the destruction of 

 ancient gravels, pointed to a travelling beach ; and the state of the 

 shells, very few of which were whole, agreed with this view. 



Mr. Whitaker asked if the author had attempted to compare the 

 sands with shells of East Anglia with those of Moel Tryfan. 



Mr. Blaee objected to the views of Dr. Carpenter, by pointing 

 out that the Chalk, which is said to be a deep-water formation, yet 

 exists at considerable heights above the present sea-level. 



Dr. Woodward referred to the value of the collection of shells of 

 existing species found at great elevations by the recent Arctic Ex- 

 pedition. 



The President stated that some very delicate shells were found 

 entire and uninjured at Moel Tryfan. 



The Author (in reply) said that the Moel-Tiyfan deposit was not 

 strictly a glacial one. The fauna has a Norwegian rather than an 

 Arctic facies. The broken appearance of shells may be due to other 

 causes than glacial action. He stated that some of the Moel-Tryfan 

 shells (e. g. TeUina balthica) are quite perfect. 



2b2 



