44 CATALOGUE OF 



('ROM Ell I AX. 



NORFOLK, EAST. EN. 



Sheiringham [31. P. G.J ; West llunton [A. S. K.J [31. P. G.]. 



PLIOCENE. 



NORFOLK, EAST. EN. 



Bramerton Common [X. M.]. 



This is a very widely distributed species on the Continent and 

 is met with from Iceland [F. H. Sikes Coll.] and Lappland 

 [Odhner Coll.] to Sicily, and from France to Lake Baikal. From 

 this last locality it has been received under several names including 

 that of /'. dubittm, Lindholia (95, p. 85). 



On the other hand authentic fossil records are at present scarce. 

 It has been recorded from the Holocene of Denmark [Johansen 

 (85, p. 9)]; seen from the Pleistocene (Campinien) of Soignes, 

 Belgium [Mas. Hist. Nat. Brussels] ; and mentioned as met with 

 in the Pleistocene (Mosbacher Sand) of Mauer (near Heidelberg) 

 [Geyer (69, p. 96)]. 



It is possible that the P. capellinii, Sacco (151, p. 437), from 

 the Pliocene of Piedmont may be a flattened form of this species. 



4. Pisidium nitidum, Jenyus. 

 [Pis. I, f. 9 ; III, f. 6 ; XIX.] 



1832. Pisidium nitidum, nobis : Jeuyns, Trans. Cainb. Phil. Soc. iv, 



p. 304, pi. xx, f. 7 & 8. 



1843. Cyclas nitida, Jenyns: Hanley, Cat. Rec. Bivalve Shells, p. 90. 

 1854. Pisidium incertum, Nob. : Normand, Coup d'osil Cyclades Nord, 



p. 6. [Quotes Jenyns sp. & fig. as synonym !] 

 Pisum nitidum, Jenvns: Deshaves, Cat. Conch. Brit. Mus. ii, 



p. 277. 



18-58. Musculium nitidum, Jenyus : Adams, (inn. Rec. Moll, ii, p. 461. 

 1859. ? Pisidium pusillum, var. Musalis . Jeffreys, Ann. & Mag. Nat. 



Hist, in, iii, p. 37 : id., Brit. Couch, i, 1862, p. 24. 



1873. ? Pisidium pileus, n. sp. : Clessin, Correspond. -Bl. zool.-min. Ver. 



Regensburg, xxvii, p. 150. 



Pisidium fossarinum, 8. acuminatvm, Clessin : Clessin in Wester- 



lund, Fauna Moll. Svecise, p. 545. \_Cf. specimens in Noruiau 

 Coll., B.M. 98. 5. 20 : 22253-54.] 



1874. Pisidium sphceriiforine, n.sp. : Clessin in Fedchenko, Jzvyest. imp. 



Obshchest. Lyubit. Estestvoz. Antrop. i Etnogr. Moskva, xi, 

 yuip. 1, p. 38, pi. iii, f. 33. 



1909. Pisidium t/ranum, n. sp. : Liudholm in Korotneff, Wissensch. 

 Ergebn. Zool. Exped. Baikal-See, iv, p. 87. 



This is a somewhat polymorphic form and its extreme variations 

 have been frequently mistaken for small P. casertanum, P. person- 

 aturn or P. pusillum. 



Jenyns, who was the first to separate it as a species, thus describes 

 it (83, p. 304) : 



