SMART AND COOKE : MARINE SHELLS OF SCILLY. 299 



Cerithium reticulatum DaCosta. — Living under rocks below 

 Cromwell's Castle; abundant from the Menavawr dredgings. 



C. perversa m L. — With the above in deep water dredgings, 

 common. 



Cerithiopsis tubercularis L. — With the above, quite 

 common and rather large. 



C. Metaxa Delia Chiaje. — About half-a-dozen dead but perfect 

 specimens of this rare and lovely shell were found, on 

 carefully examining the dredged sandy gravel, from outside 

 Menavawr. 



Purpura lapillus L. — Fairly common all round the rocky 

 shores, but never clustering very thickly ; the uniform colour 

 is white : banded specimens seldom or never occur. One 

 variety, found along the inner channels and on rocks in 

 more sheltered places, has a very sharp and produced spire, 

 with the whorls strongly corded, and almost a keel on the 

 shoulder, mouth narrow, canal long ; specimens occurred 

 1-3 inch long and only about half that breadth. Another 

 variety, from the exposed outer rocks, is an exact opposite 

 to this, being of a squat dumpy form, spire scarcely any, 

 mouth large and rounded, occupying nearly "875 of the 

 whole shell. If these two forms only of jP. lapillus occurred, 

 they would certainlv have been made into different species. 



Buccinum undatum L. — Very old and worn shells only, 

 washed up on the beaches ; exceedingly rare. 



Murex erinaceus L.— Strangely rare, never found living in 

 the recess of the tide, once dredged alive outside Mena- 

 vawr ; dead shells, mostly much worn and encrusted, occur 

 sparingly in the dredgings. 



Lachesis mininna Mont. — Common in gravel, from the deep 

 water dredgings. 



Trophon muricatus Mont. — Sparingly found in the deep 

 water dredgings outside Menavawr. 



T. truncatus Strom. — One dead and worn specimen with 

 T. vmricatus. The locality is noteworthy, Tenby being 

 the southernmost locality given by Jeffreys. 



