CYCLOSTOMA. 305 



Shell globose-oval, rather solid and opaque, scarcely giossy 

 (owing to the strong sculpture), yellowish-brown with more or 

 less of a reddish tinge and often marked with irregular streaks 

 or spots of reddish-brown or purple, sometimes plain yellow or 

 fawn-colour; the spots sometimes form three or more in- 

 distinct and interrupted rows on the body whorl ; sculpture 

 consisting of strong spiral ribs, of which there are about forty 

 on the last whorl, and of much liner but more numerous trans- 

 verse ribs, which do not cross the mam ribs but intersect the 

 interstices, giving that part of the surface a somewhat reti- 

 culated appearance : periphery rounded: epidermis thin: ivliorls 

 4^, exceedingly tumid, the last occupying considerably more 

 than two-thirds of the shell ; upper whorls purple or yellow- 

 ish-brown and quite smooth: spire bluntly pointed: suture 

 very deep : mouth circular, with the exception of a slight angle 

 at the upper part : outer lip and inner lip rather thick, very 

 slightly reflected, and forming a complete peristome : imihili- 

 cus twT-sted, but rather deep : operculum flat, composed of about 

 five whorls, strongly and closely marked with oblique and flex- 

 uous striae ; nucleus depressed, smooth, and of a darker colour, 

 like the nucleus or apex of the shell. L. 0-6. B. 0-4. 



Habitat : Under stones and at the roots of fern and 

 farze in many parts of England_, Wales^ and Ireland, 

 from Yorkshire to Alderney. It appears to frequent 

 chiefly the sea-coast and calcareous soils ; but it occurs 

 in Northamptonshire and Oxfordshire (inland counties), 

 as well as in parts of Norfolk where there is no chalk. 

 It has not been recognized wdth any degree of certainty 

 as a fossil of our upper tertiaries. Its foreign range is 

 southern, and includes Central Germany, France, Italy, 

 and Portugal ; and it extends to the Canaries. Donegal 

 Bay appears to be its most northern limit. 



Lister gave, nearly two centuries ago, some excellent 

 details of the physiology of this mollusk; and in 1828 

 another of our countrymen (the Rev. M. G. Berkeley) 

 published, in the ^ZoologicalJournaP (vol. iv. p. 278-284), 

 further particulars of its anatomy. According to Moquin- 

 Tandon it is a vegetable feeder ; and the structure of its 



