10 



it is less ventricose than any other variety which I have 

 seen. There is also a straw-coloured variety, found in 

 the vicinity of Beeston, which is only slightly ventri- 

 cose, and semi-transparent. 



The localities are too numerous to mention ; we 

 shall therefore only give a few of the principal ones. 

 The river Trent, near Beeston; the river Leen, near 

 Bulwell; the various brooks at Lenton, Beeston, Bul- 

 well, Highfield House, Attenborough, Sawley, and in 

 the Nottingham Meadows. Common in ponds at Pen- 

 zance (Millet), Bristol and Wiltshire (Montagu), the 

 river Thames (Millet), Gateacre near Liverpool (Win- 

 stanley), Kendall (Gough), Newcastle (Alder), Darling- 

 ton, Durham (Graham), Dublin (Brown), Germany 

 (Pfeiffer), and Sweden (Nilson). 



Professor Forbes says it is fossil in the fresh-water 

 strata of the Pleiocene ages, in the valley of the Thames. 



Cyclas caliculata (The Capped Cycle). Drapamaud. 

 Figures 5 and 6. 



O 



5 



<3> 



6. 



This delicate, semi-transparent, almost white shell, 

 is much flatter than the other members of the Cyclas 

 family, being very compressed, except near the umbones. 

 The umbones are narrow, project, and, as the name of 



