GASTEROPODA. 319 



S. Serpuloides, Mont. Dublin Bay, Turt. C. D. 



Genus Valvata. 



V. piscinalis, Lam. 



Common, and generally distributed over Ireland. Many of my mid- 

 dl^sized specimens correspond with Pfeiffer's V. depressa, in so far as 

 the figure and diagnostic description enable me to judge, Pfeiff. part i. 

 p. 100, t. 4, f. 33. See Gray, Man., p. 9S. This species is very vari- 

 able in the degree of elevation of its spire, and consequently in its diame- 

 ter relatively to its height. I have been favoured by Edward Waller, 

 Esq., with specimens of this Valvata collected at Finnoe, County Tippe- 

 rary, the volutions of which appear angular, from being spirally cut, as 

 they occasionally are in various species of Liinneus, and the angles are 

 marked with a white line. 



V. cristata, Mull. 



This handsomely-formed species is distributed over the island. 

 The Valv. Planorhis, Drap., noticed as Irish in Lond. and Edin. Phil. 

 Mag., 1834, p. 300, must be erased from the list. 



Family TUOCHID.E. 



Genus Neritina. 

 N. Jluviatilis, Lam., 

 Is found in the East, West, and South of Ireland. The localities given 

 by Capt. Brown are, — " In a stream at Clonoonej', in the Shannon, and 

 Bresha ; and in some places of the canal, adhering to stones,"' p. 532. In 

 the vicinity of Dublin it occurs in the Grand Canal ; at Lough Derg, and 

 Limerick, it is found in the Shannon ; and in the County of Tipperary, 

 in some of the tributaries of this river ; and about Cork, in the river Lee. 

 The specimens which I possess from the Shannon and Grand Canal are 

 identical with the N. Jiuviatilis, represented by Kossmassler, and as dis- 

 tinguished from the N. Damibialis, K. strungidata, and N. transversalis. 

 Icon, part 2, p. 17, 18, pi. 7. 



Genus Phasianella. 

 P. 2)ulla, Brown. 



Littoral in some localities, dredged in from about 6 to 10 fathoms in 

 Belfast Bay, common. 



Genus Trochus. 

 T. Magus, Turt. 



This common species, though not numerous in individuals, in so far as 

 it has come under my notice, is doubtless found at all the localities set 

 forth. It is not included in all the lists put before me. On the Avcstern 

 coast I have met with it at the South Islands of Arran ; Killery, Clifden, 

 and Clew Bays. In our North-eastern Bays it is occasionally found alive 

 between tide-marks, but its general haunt is where the water is several 

 fathoms, 8 to 10, &c., in depth. 



T. umbilicatus, Turt. 

 Common, and in numbers on gravelly shores. 



