33 



JOURNAL OF CONCHOLOGY, 



Vol. 14. APRIL, 1913. No. 2. 



ADDITIONS TO "BRITISH CONCHOLOGY." 



By J. T. MARSHALL. 



Part VII. [continued from vol. ij, p. 338). 



P. angulata Jeff. — The animal of this species has hitherto been 

 undescribed. The following description was taken from several 

 specimens procured from fish stomachs, and necessarily in a more or 

 less collapsed state — Body oblong, completely covering the shell ; 

 colour dirty white with a tinge of red ; hinder part lobed; margin of 

 mantle plain; gizzard very minute. 



From low water of spring tides to 80 fathoms. Southport (Chaster)! 

 Brora, from haddocks (Baillie)! off St. Martin's Point, Guernsey, 

 2 2f. ; Scilly Isles 35f. ; St. Ives and St. Mawes, Cornwall; Eddy- 

 stone 3of. ; Livermead, Torquay, a live specimen from weed; Tenby; 

 off Southport i2f. ; Skegness, Killala Bay, Portrush, off Loch Ryan 

 27f; Mull of Cantire 4of.; Dornoch Frith; West Orkneys 45f.; 

 East Shetland 8-1 of. 



var. circumlustra Marsh., Journ. of Conch., 1893, vol. vii., 

 p. 264. — Scilly, Eddystone, Tenby, Killala Bay, Portrush, Dornoch 

 Frith, West Orkneys, 45f. 



P. angiilata would now appear from the above records to be 

 generally diffused on our coasts, but it is everywhere rare, although 

 my cabinet contains nearly 100 specimens. Mr. William Baillie, of 

 Brora, writes me that he finds a specimen in almost every batch of 

 haddock offal he examines, "generally associated with starfish 

 remains," and that "it occurs on all the fishing-grounds frequented 

 by the Brora and Golspie fishermen." It is possible that they are 

 commensal or parasitic on starfish, either on the latter's body or on 

 its rays, and are thus carried over the sea-bed and become a prey to 

 the haddock. The lines of growth on the shell are rather con- 

 spicuous, and aged specimens become thickened by additional layers; 

 they are otherwise very fragile and brittle, and the extended wing- 

 like outer edge of the crown is rarely present in dead specimens. 

 The young are smooth and glossy, and the apex is partially intorted, 

 as in the next species. 



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