VENUS. 341 



in the north of England ; but in these cases the shells 

 may have been introduced among ballast. That mode 

 of importing extraneous shells into our sea-ports has 

 happily ceased, owing to the great care taken of late 

 years to prevent the discharge of ballast in or near any 

 tidal harbour. More mischief was caused to navigation 

 than to conchology by previous neglect of the above 

 precaution. V. verrucosa is common in the south and 

 west of Ireland. Sussex tertiaries (Godwin- Austen) ; 

 Wexford beds (Sir Henry James) ; Coralline Crag (S. 

 Wood). It does not appear to inhabit the north of 

 Europe. South of Great Britain it has been found every- 

 where, from Brittany to the iEgean and the Canaries, in 

 2-60 fathoms. Dr. Menke considers a species from 

 St. Vincent to be identical with ours. 



The animal is occasionally eaten in some of the 

 Channel Isles, and habitually in county Clare. Wein- 

 kauff mentions that it is sold in the market at Algiers. 

 V. Casina is its nearest British analogue ; but the pre- 

 sent species may be always recognized by its more 

 globose form, its coarse and rugged look, the ridges 

 being nodular or warty, and regularly equidistant (in- 

 stead of numerous in the umbonal part and few on the 

 main portion of the shell), and by the longitudinal stria 

 being much stronger and more like fine ribs. 



Linne compared the shell with his V. Paphia, of which 

 he unaccountably supposed this might be a smooth 

 variety. In the ' Gazophylacion ' of Petiver it is called 

 the " Cornwalle hearte-cockle with rugged girdles/ 5 It 

 is the " Clonisse " of D' Avila, and Pectunculus sirigatus 

 of Da Costa ; and in its younger state it is probably the 

 V. subcordata of Montagu, V. cancellata of Turton's 

 1 Conchological Dictionary/ and V. Lemanii of Pay- 

 raudeau. 



