of the North of Ireland. 85 



and from Dickie's lists it would appear to live in profusion in Strangford 

 Lough. 



Trochus cinerareus, Linne. 



One of our most common species, living on stones and sea-weed between 

 tide-marks and in depths up to 25 fathoms, throughout the province. 

 Hyndman dredged a single living specimen in the great depth of 70-90 

 fathoms off the Maidens. It is locally called " silver- shell," on account of 

 the pearly lustre of the inner layers. The T. littoralis, Brown, for which 

 Thompson, quoting from an older writer, mentions Killough as a station, 

 belongs to the present species, and, according to Jeffreys, can scarcely be 

 considered a variety. 



Trochus umhilicatus, Montagu. 



Between tide-marks, among stones and Fuci ; common. 



Trochus Duminyi, Requien. 



Our rarest shell, Bundoran in Donegal Bay being its only British habitat. 

 It appears to be of rather rare occurrence there, where it was first discovered 

 some years ago by Edward "Waller, an assiduous and distinguished Ulster 

 conchologist. 



Trochus lineatus, Da Costa. 



"This littoral species, found on rocks, stones, &c, is unknown to me 

 further north on the Eastern line of coast than Ballywalter, Co. Down 

 (54£° lat.). Southward it is common " — Thompson {sub Monodonta erassa). 

 On the western side of the province it flourishes at Bundoran, in just the 

 same latitude — "Waller, Jeffreys, and others. 



Trochus Montacuti, W. Wood. 



Sparingly but widely distributed on the Antrim and Down shores. Hynd- 

 man dredged it alive off Ballygalley Head, Waller off Groomsport, and Dickie 

 in Strangford Lough and the open channel adjoining — depths ranging from 

 12 to 25 fathoms ; in a dead state it occurred frequently, especially on the 

 Turbot Bank (sub T. Montagui). A very elegant scalariform monstrosity was 

 dredged off Lame, as noted by Hyndman and Jeffreys. 



Trochus striatus, Linne. 



"Dead, in Turbot Bank sand, Mr. Jeffreys" — Hyndman, 1859 Report; 

 specimens from that locality are in the Belfast Museum Collection. In his 

 " British Conchology," the most northern station which Jeffreys gives is 

 Dublin Bay. It is a southern species, and frequents the Channel Islands and 

 south coasts of England and Ireland. 



[Trochus ezasperatus, Pennant. 



"Turbot Bank, Dr. Dickie, doubtful"— Hyndman, 1857 Report (sub T. 

 exiguus). This is the only note of the occurrence of the present species. 

 Jeffreys regards as doubtful all localities other than those on the South of 

 England coasts and Channel Islands.] 



