GASTEROPODA. 31o 



species inhabits oozy tracts. The only locality worthy of special notice is 

 a brackish lake in the largest of the South Islands of Arran, whei-e an 

 elongated variety was obtained by Dr. Ball and myself in the summer of 

 1834. 



L. saxatilis, John. (W. T., Ann. N. H., vol. v. p. 12.) 

 Found sparingly in the localities indicated in the table. 



L. Neritoides, Forbes. 

 Common around the shores. 



Genus Lacuna. 

 L. jmteola, Turt. 

 Kilkee (County Clare) may be added to the other habitats whence I 

 obtained it in shell-sand ; it is not uncommon on some parts of the 

 western coast. Ardmore, Mrs. Mackesy. 



L. 2^111(11(1(1, Turt., 

 Inhabits the Laminai-ican region in Belfast and Strangford Loughs, 

 and chiefly found on the broad fronds of Laminaria dujitata ; also on 

 oysters : occurs but sparingly ; procured in some quantity at Ballycastle 

 by the Rev. Thomas Hincks. Frequent at Miltown Malbay, Prof. Har- 

 vey. Dredged in Clew Bay by our party in 1840. 

 Ardmore, Mrs. Mackesy. 



L. crassior, Turt. Br., 

 Inhabits the same region as L. paJlklnla in the two first-named localities, 

 and generally found feeding on the tangle. Dublin Bay is noticed on the 

 authority of Turton only. Dr. Farran includes it among the species pro- 

 cured at Birterbuy Bay ; but it is not in Mr. Barlee's list from that 

 locality. 



L. quadrifasciata, Br. Turt. 

 A common species, inhabiting the same region and found on the same 

 plant as the two last, but much more numerous : met with in shallower 

 water. Dredged in Clifden and Clew Bays (3 — 12 fathoms) by our party 

 in 1840 ; a green variety was found on Zostera marina in the latter lo- 

 cality. The var. L. vincta is not uncommon ; L. canalis is more so. 



Genus RissOA. 



H. cimex, Linn. 



" Portmarnock, among loose stones and sand at high-water mark," 



Brown. I have seen specimens thence collected by Mr. Warren. Found 



very sparingly in shell-sand thence and from Bundoran. Ardmore, Mrs. 



Mackesy. I have obtained them more commonly at Brook, Isle of Wight. 



Ji. striatula, Mont. (W. T., Ann. N. H., vol. v. p. 12.) 

 In shell-sand, Dublin ; Bundoran ; Malbay ; Ardmore, Mrs. Mackesy. 



R. costata, Turt. 



This species, like the two last, is chiefly found in shell-sand, but is more 

 numerous in individuals as well as being more widely distributed on our 

 coasts. 



Wherever they have occurred to me this also Avas found ; — a remark 

 which applies to the Isle of Wight as well as to the Irish shores. 



