CONCHACEA. 119 



amnica, Turton, Brit. Biv., p. 250, pi. 11, f. 15 ; lb., Man., p. 

 15, f. 5 ; Cyclas amnicus, Fleming, Brit. An., p. 453 ; Tellina 

 amnica, Gmelin's Linne, I, p. 3242, No. 78; Miiller, p. 205, No. 

 389; Tellina rivalis, Linn. Trans., IV, p. 187; Donovan, Brit. 

 Sh., II, pi. 64, f. 2 ; Cardiiim amnicum, Montagu, p. 86 ; 

 Pisidium amnicum, Thompson, Ann. and Mag. Nat. Hist., VI, 

 p. 54. 



Shell thin, subpellucid, of a brownish or grayish horn-colour, 

 obliquely oval, moderately convex, and sulcated concentrically, 

 with the furrows finely striated; beaks tumid, a little produced, 

 and placed considerably towards the anterior side ; left valve 

 provided with a double central tooth, and two lateral teeth on 

 each side, standing parallel one within the other, the outer of 

 which is very small ; right valve with two cardinal, appoximating, 

 oblique teeth, with one lateral tooth on each side, that on the 

 posterior side strong, and elevated above the margin of the 

 shell ; inside bluish-white, dim in the disk, but glossy towards 

 the margin ; on each side are distinctly visible, large, smooth 

 spaces, to which the muscles adhere. Length three-eighths of 

 an inch ; breadth half an inch : although it is but rarely met 

 with of this size. 



Found in slow running rivers and streams, and is known to 

 inhabit the Avon, Wiltshire ; in the water-courses in the mea- 

 dows near Wareham, Dorsetshire ; the Litfey, Ireland, near 

 Sallins, Kildare, and in rivulets which run through the bog at 

 that place ; in a stream near Clonooney, Kings County ; we 

 have also met with it in a stream, which empties itself into the 

 Water of Leith, a little way above Colt Bridge, near Edin- 

 burgh ; and many other localities. 



2. Pisidium fontinale, pi. XXIII, f. 8. 



Pisidium font inale, PfeifFer, Land un Was. Sn., p. 126, pi. 

 5, f. 15, 16; Brown, Edin. Journ. Nat. and Geo. Science, I, 

 p. 11 and 413, pi. 1, f. 5, 6, 7 ; Cyclas fontinalis, Drapernaud, 

 Hist, des Moll., p. 130, pi. 10, f. 11, 12; Lamarck, An. San. 

 Vert., V, p. 559, No. 7; Cyclas pusilla, Turton, Conch. Diet.; 

 lb., Brit. Biv., p. 251, pi. 11, f. 16, 17 ; lb., Man., p. 16, f. 7 ; 

 Pisidium pulchellum, Jenyns, Monog., p. 18, pi. 21, f. 1 ; 

 Thompson, Ann. and Mag. Nat. Hist., VI, p. 53 ; Forbes, 

 Mai. Mon., p. 50; Pisidium fontinale, Brown, Illust. Conch., p. 

 94, pi. 39, f. 23. 



