42 



In Ireland, near Dublin (Brown); generally dis- 

 tributed throughout the island (Thompson). 



I am not aware that it is found in Scotland. 



Professor Forbes says that it is generally distributed 

 throughout Europe. It is described amongst the Ger- 

 man shells by Pfeiffer, amongst the Swedish ones by 

 Nilson, as an inhabitant of Sicily by Philippi, and of 

 France by Grey. 



It first occurs as a fossil in the mamraalliferous crag 

 (Forbes). 



BiTHiNiA Leachii (Dr. Leach's Bitbinia). Sheppard. 

 Figures 18 and 19. 



Bithinia Leachii was added to our list of fresh water 

 shells by Mr. J. E. Grey, of the British Museum, in 

 the year 1821, under the name of Bithinia ventricosa; 

 this latter name it has usually borne, until Professor 

 Forbes changed it, with good reasons, to B. Leachii. 



This shell is thin, semi-transparent, and spiral, being 

 very ventricose. It is horn-coloured. There are four 

 or five convolutions, which are swollen, and deeply 

 divided. The mouth is wide and nearly round, or ap- 

 proaching that of an oval. It has a small umbilicus. 

 The usual size is 3 lines long, by 2^ lines broad. 



Bithinia Leachii may be looked upon as a somewhat 

 rare shell, being almost confined to the south of Eng- 

 land; it occurs here, however, in one or two places, 

 but not very abundantly. 



