438 BULLION. 



the spire : outer lip more or less curved, not folding inwards ; 

 it projects beyond the crown : inner lip forming a broad and 

 flexuous glaze : pillar short, solid, smooth, and curved. L. 1. 

 B. 0-75. 



Yar. glohosa. Smaller, thinner, globular, pale yellowish- 

 green or creamcolour. 



Habitat : Mud-flats and ooze in the littoral and 

 laminarian zones^ on the coasts of Hants, Dorset, Devon, 

 and Cornwall; Sark, in 15-20 f. (J. G. J.) ; Jersey 

 (Dodd and Jordan); Manorbeer, near Tenby (J. G. J.); 

 Birterbuy Bay, co. Gal way (Farran); Ban try Bay (Mrs. 

 Puxley and Leach) ; Cork Harbour (Humphreys); Bal- 

 briggan in Dublin Bay (Turton); ? Scarborough (Bean); 

 ? Dunbar (Laskey). A local species. The variety was 

 taken by Mr. Clark at Exmouth. It is impossible to 

 define exactly the geological and geographical range of 

 B. hydatis', because two European species have been 

 confounded by authors under that name. It is said by 

 Cantraine and others to occur in the Italian tertiaries ; 

 and there is no doubt that it inhabits the Atlantic shores 

 of France and Portugal, both sides of the Mediterranean,, 

 the Adriatic^ and ^Egean^ at depths of 0-69 f. ; Canary 

 Isles (M*" Andrew). 



More than thirty years have elapsed since I had the 

 good fortune to observe, in company with my late friend 

 Mr. William Clark, hundreds of these creatures, in the 

 shallow and slushy pools left by the tide near high-water 

 mark on Dawlish Warren; soon afterwards, owing 

 to a shifting of the sands, these pools disappeared, and 

 with them the Bulla. When it swam or floated, the 

 side-lobes of the foot were withdrawn from the shell and 

 spread out like a pair of fins. The shell is occasionally 

 distorted, having either a rude spiral groove below the 

 apex or a depression behind the pillar. 



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