34 The Irish Naturalist. March, 



Dingle shells has shown us that the original opinion was 

 correct and that they are referable to forms of P. hibernicum 

 and not to P. ohtusale. 



P. hihernicmn was next recognised — by Mr. B. B. 

 Woodward — among shells collected during the Clare 

 Island Survey in L. Gowlanagower, on Inishbofin, West 

 Galwa}^ By 1913, when his Catalogue^ w-as published, 

 Mr. Woodw^ard had also found it amongst shells from 

 Tullaghnafrankagh L., South Galway, and was able to 

 record it from the Takern See in Ostergotland, Sweden. 

 In 1914 we began to study critically the numerous " locality 

 sets " of Pisidia, w^hich we had accumulated during some 

 years of assiduous collecting throughout Ireland. This 

 material, representing our own gatherings from upwards of 

 five hundred localities, had been laid aside to await a 

 favourable opportunity for study and in the expectation 

 that with Mr. Woodward's monograph before us, the 

 identification of our specimens would prove a more easy 

 task. 



Our first additional specimens were discovered while 

 working out the fossil mollusca which occur in the shell- 

 marls of the White Bog, near Killough, Co. Down, Mr. 

 Woodward subsequently agreeing with our identification 

 of the shells from these deposits. Soon afterwards we 

 detected it in gatherings from many localities and came to 

 regard it as a widely distributed shell in Ireland, a con- 

 clusion which, we think, is fully justified on perusal of the 

 list of Irish records given below. 



The first specimen to come to light from England w^as one 

 collected in 1908 by A. W. S. in a ditch by the Thames at 

 Kew Gardens, Surrey, but as it was considered improbable 

 that P. hiherniciim should occur there, it w^as relegated for a 

 time to the position of " ? P. nitidiim." Other specimens, 

 however, soon put in an appearance, as amongst a large series 

 of shells received from Mr. J. E. Cooper, two sets were found 

 to contain P. hibernicum — one from Gaerwen, Anglesey, and 



1 Cat. of Brit. Species of Pisidia, cS-c [Afterwards referred to herein 

 as " Cat."]. 



