38 Mr. Jeffreys on British MoUusca. 



from Scarborough. Judging from the description and figure given 

 by PoH in his * Testacea utriusque SiciHai,' t. i. p. 65. pi. 16. f. 1, 

 I should say that his P. Casertanum ought to be referred to this spe- 

 cies, and not to P. Henslowianum ov pule helium, as M. Baudon has 

 supposed. Poli did not notice any other species. There being a 

 difference of opinion on this point (probably arising from the descrip- 

 tion not being sufficiently explicit for identification of the species), 

 it would not, in my opinion, be worth while to substitute the local 

 name of Casertanum for either of these species, which are so well 

 known by their present names. 



Pisidium nitidum, ii. 126. Yatton, Somerset (Rev. Mr. Norman) ; 

 Serk, with the last and two next species. It appears to be generally 

 diffused throughout Great Britain and Ireland, but not to be so 

 gregarious, or to occur in such numbers, as the last species. 



P.roseum, Scholtz,Schlesien's Land-undWasser-Mollusken,p. 140. 

 P. pulchellwn, var. I, Jen. p. 18. pi. 21. f. 4, 5. P. Gassiessianum, 

 Dupuy, Moll. terr. et d'eau douce en France, p. 685. t. 30. f. 7. 

 This species differs from any of its congeners in the colour of the 

 animal, from which the name given to it by Scholtz is derived, as 

 well as in its gibbous shell, and the front or ventral margin being 

 much compressed. It is found, but in comparative rarity, together 

 with P. nitidum and Henslowianum (var. pulcheUum), so that it 

 cannot be a local variety of either of these species ; and the position 

 of its beaks, which is nearly terminal, will at once serve to distinguish 

 it from P. pusillum or any of its varieties. I have taken it in many 

 parts of England and Wales, as far north as Nottinghamshire ; and I 

 observed it, in 1 843, in a pond by the road-side between Bonn and 

 Poppelsdorff in the Rhine district. A comparison of Mr. Jenyns's 

 typical specimen of P. pulchellum var. ^. with this species has satis- 

 fied me that they are the same. I have added a representation of it 

 in PL II. f. 3 a-c. It was not without considerable hesitation that 

 I adopted Scholtz' s name of roseum for this species, because in a 

 Supplement to the second edition of his work, which was published 

 in 1853, he has considered it to be a variety of the P. fontinale of 

 Pfeiffer (our P. pusillum) ; but the pecuhar and constant colour 

 of the animal appears to form a good distinctive mark, and Scholtz 

 has not otherwise characterized any of the Pisidia with sufficient 

 accuracy. 



P. Henslowianum var. pulchellum, ii. 1 28. Guernsey (Dr. Lu/cis). 



Ditto (typical form), ii. 131. Ferry Hill, co. Durham (Rev. Mr. 

 Norman) . 



The P. Recluzianum of Baudon* s monograph, p. 53. pi. 5. f. D, 

 which is stated to have been found at Belfast, appears, from the de- 

 scription and figure given by him, to be the Turtonia minuta. He 

 even states the colour of the shell to be *' flavo-violacea," which is 

 precisely that of T. minuta. Mr. Hyndman says, as to this species, 

 *' Abundant between tide-marks. Found in great quantity in the 

 stomachs of mullet taken in the Harbour near Belfast. In one fish 

 taken in Larne Lough, and the contents of the stomach given me by 

 W. Darragh, Curator to the Belfast Museum, I estimated 35,000 of 



