316 MOLLUSCA. 



R. rubra, Adams. 



Dublin coast, Tui'toii ; M. Malbay (Prof. W. H. Harvey) ; sent me from 

 lloundstone by Mr. M'Calla, in IS'iO, as found there, but as rare, about 

 the roots of Algce growing on the exposed shores. In shell-sand from 

 Kilkee. Among sea-weed brought from Tory Island (off the North coast 

 of Donegal) by Mr. Hyndman in 1845, this species, together with R. 

 parva and R. interrujda, was found. 



R. interrupta, Br. Turt. 

 One of the more common species around the coast, frequenting chiefly 

 soft sand and ooze ; littoral and at a few fathoms. 



R. proxima, Alder. 



This is the R. vitrea of my report on the Fauna of Ireland ; it was con- 

 sidered at that time by Mr. Alder to be so. 



M. Malbay, Prof. Harvey ; Magilligan (W. T.) ; Portmarnock (W. T.) ; 

 Bundoran (Mrs. Hancock) ; Bantry Bay. 



R. nivosa, Mont, Dublin Bay, Turt. 



R. unifasciata, Mont. As last. 



R. cingilla, Br. Turt., 



I have met with attached to stones in gravelly and muddy pools, betw^een 

 tide-marks, on all sides of the coast. Mr. M'Calla, in sending me speci- 

 mens from Roundstone, stated that he found it there among Kellia rtibra 

 on the exposed rocks, inhabited by 3Tytilus incurvatus, as Avell as under 

 stones on muddy banks. Ardmore, Mrs. Mackesy. 



Var. rupestris, Forbes. 

 Dublin coast, T. W. Warren, Esq. ; North-East coast, Mr. Hyndman 

 and AV. T. : not rare. 



R. alba, Adams. (W. T., Ann. N. H., vol. v. p. 12.) 

 Youghal, Miss M. Ball. 



R. Bailies, mihi. 



Elongated ; white ; apex obtuse ; 5 slightly-rounded whorls, deeply 

 marked longitudinally with somewhat distant striae ; aperture ovate ; 

 margin of the mouth thin ; lower portion of the first whorl spu-ally striated ; 

 length H line. 



Although of a more slender form, this species, in sculpture, &c., some- 

 what resmbles Odostomia spiralis, but is a true Rissoa. 



Found at Youghal by Miss M. Ball, after whom it is named, though a 

 very trivial compliment to that lady's acquirements in different depart- 

 ments of the Invertebrata of Ireland. 



R. semistriata, Mont. 



In the Annals of Natural History, vol. v. p. 98 (1840), the following 

 description was published : — 



" Rissoa tristriata, mihi. 



" Conic ; volutions 5h \ rounded, smooth, with spiral rows of tawny 

 spots ; first whorl very large ; aperture roundish oval ; umbilicus none ; 



