36 Proceedings of the Eoyjl Iriih Academy. 



six feet in height. Jfytiltts edulk, which lives in thousands on the 

 gtuTounding flats, constitutes about ninety per cent, of the whole, but 

 the remainder include a number of species which do not now live in 

 the immediate vicinity — 



Ostrea edulis. f. TrocJius cmerareu.s. r. 



Anomia epTiippium. v. r. Lacuna divarwata. v. r. 



Peeten tarius. v. r. Littorina litorea. v. r. 



P. operculari^. v. r. L. rtidis (juv.). r. 



Nucida nuihus. v. r. Z. ohiusafu. f. 



Venus galJina. v. r. Pissoa m-etnhranacea. f . 



Tapei aureus, f. R.parva. r. 



Cardium eduls (juv.). r. R. alheJh. v. r. 



C. echinafum. v. r. Hydrohiu ulvcB. r. 



C. exiguum. v. r. TurriteJJa Urehra. r. 



Lucina horealis. v. r. Ododomia unidenfata. f. 



Telh'na laltkiea. v. r. Cen'thium reficuhtum. c. 



Mactra suhtrxtmata. v. r. Natica catena, v. r. 



Mya arenan'a. v. r. Ifasm incrassata. f. 



Corbula gihha. v. r. Pleurotoma rufa. t. 



The rarity of Cardium eduh, Tellina lalthica, Sydrolia ulvce, and 

 Jfya arenaria, which live in great abundance in the vicinity, as quite 

 as noteworthy as the occurrence of many shells which are not now 

 inhabitants of the neighbourhood. This accumulation may be paral- 

 leled with the wonderful shell-banks of Lough Foyle, which have 

 been referred to by Portlock,^ from which, at the time he wrote, over 

 59,000 tons of shells, chiefly T. terebra, were removed annually, with- 

 out any failure or diminution in the supply. In that case, as in 

 the present, most of the shells cannot have lived in the vicinity, but 

 must have been brought by tidal currents. 



EXLBOOT. 



The raised beach at KOroot was mentioned, and a short list of its 

 shells given, by Hull, in 1872,* the species recorded being Anomia 

 ephippium, Cardium edxtU, Patella culgata, Trochus umbilieatm, Litto- 

 rina litoraiis, L. litorea, Cerithium reticulatum, Kassa reticulata, 

 Buccinum undatum. In the !5Iemoir to Sheets 21, 28, and 29 of the 



•• Geology of Londonderrv," Lc, 1843, p. 163. 

 Eepoit of Brit. Assoc., 1872. 



