12G CYCLADID^. 



much produced, and sometimes are slightly capped, as in 

 Cyclas caliculata. 



A variety exists which is rather more ventricose, and 

 produced at the umbones. 



The length is one-fifth of an inch, and the breadth nearly 

 two lines. 



It inhabits ponds, at Scarborough (Bean), in the north of 

 England (Alder), Preston (Gilbertson), Clumber Lake in 

 Nottinghamshire, the Croydon Canal, and at Cadley, near 

 Swansea (Jeffreys), Bath and Exmouth (Clark). 



It is widely distributed, although not common, through- 

 out Ireland (Thompson), as in various parts of Antrim, in 

 a moist spot in the wood at Holywood House in Down 

 (and elsewhere in that county), at Youngrove, near 

 Middleton in Cork (C. Wright), Killereran in Galway, 

 Portarlington, and the vicinity of Dublin. In Scotland 

 it has been taken at Balmacarra, West Ross (Jeffreys). 

 The Sicilian P. australe of Philippi (Moll. Sicil. vol. i. 

 p. 125, pi. 14, f. 11) is apparently identical. 



P. nitidum, Jenyns. 



Orbicular- oval, extremely glossy, with fine strioc, and a few 

 deeper ones upon the uuibonal region : umbones rather blunt. 



Plate XXXVII. fig. 14. 



Pisidium nitidum, Jenyns, Trans. Cambridge Phil. Soc. vol. iv. p. 304, pi. 2(1, 

 f. 7, 8.— Gray, Manual of L. and F. W. Shells, p. 283, 

 pi. 12, f. 150. — Thomp. Ann. Nat. Hist. vol. vi. p. 1 95.— 

 M icuiLLiv. Moll. Aberd. p. 253. — Brown, 111. Conch. 

 G. B. p. 95, pi. 39, f. 26. 



Cyclas nitida, IIanley, Recent Shells, vol. i. p. 90, suppl. pi. 14, f. 46 (not well). 



This species can with difficulty be distinguished from 

 pusillum or obtusale, especially in the immature state, and 



