NOTES ON THE MARINE MOLLUSCA OP PORT-STEWART. 11 



*S. siliqua, var. arcuata, Jeff. — Sparingly, with the type. Not 

 mentioned in Praeger's list. 

 Thracia prcetenuis (Pidt.). — " Magilligan is the only northern 

 locality in which the species has yet been met with by Mr. 

 Hyndman or myself. It is thrown ashore quite fresh 

 there " (Thompson). I have about a dozen valves from the 

 sands of Port-Stewart. Mr. Praeger says, " I have a valve 

 found by my brother at Magilligan." It is fairly common 

 in the Clyde. 

 Corhula gibba, Olivi. — A single valve. 

 *Mya arenaria, L. — Common. 



*J/. truncata, L. — Not so frequent as the last species. 

 Saxicava rugosa (L.). — Fairly plentiful, but not of large size. 



Gasteropoda. 

 * Patella vulgata, L. — In its usual prolific abundance. 



Helcion pellucidum (L.). — Yery common along the sands, and on 



the gravel beds between Port-Stewart and Rock House. 

 *H. pellucidum, var. laivis (Penn.). — One of the most abundant 

 shells of the neighbourhood, especially among the gravels 

 above the rocks near Rock House. 



Tectura virginea (Milll.). — Frequent, but much worn. 



Emarginula Jissura (L.). — Plentifully obtained. "Thrown up 

 by the tide on sandy beaches at Castlerock and Magilligan " 

 (Praeger). 



Fissurella grceca (L.). — " Portrush — Miss Richardson. Magil- 

 ligan and Castlerock, Co. Derry, dead" (Praeger). One 

 of the most abundant shells along this coast, and frequently 

 of large size. It is excluded by Brown from his Clyde 

 fauna, though its presence was vouched for by Smith at 

 Bute; north of Holy Isle, 10-30 fathoms, by Greville and 

 Miles ; in Loch Fyne, by Barlee ; and at Lamlash, by Lands- 

 borough. Since the publication of the "Mollusca of the 

 Firth of Clyde" it has been recorded by the "Medusa" 

 from Loch Goil, in 35-40 fathoms, and in the Dunoon basin, 

 from 6-8 fathoms. It is difficult to conceive how such a 

 well-marked shell could be confused with any other species. 

 It is frequently found in Oban Bay, Tobermory, Stornoway, 

 and elsewhere on the west coast. 



