296 SMART AND COOKE : MARINE SHELLS OF SCILLY. 



Phasianella puilus L. — Abundant on Zostera in the roads, 



with Rissoa mevibranacea. 

 Lacuna crassior Mont. — Two dead specimens from the deep 



water dredgings. 

 L. pal I id u la DaCosta var. ? — One specimen from the inner 



Channel, two from deep water. 

 Littorina obtusata L. — Swarming on sea weed everywhere 



at half-tide mark. 

 L. neritoides L. — Outer rocks only, often remarkably fine and 



clean ; they seem to take their colour from the rock they 



inhabit. 

 L. rudis Maton. — Exceedingly abundant everywhere. 

 L. rudis var. sulcata Maton. — Abundant and especially fine, 



more so where the sea weed is yellow, furrows not purplish 



brown but black. Other varieties occur, but this is the 



most marked. 

 L. littorea L. — Two specimens only, found living on east 



shore of Bryher, with T. lineatus ; very rare, but possibly 



careful search amongst thousands of T. lineatus might dis- 

 cover more. 

 Rissoa cancellata DaCosta. — Menavawr dredgings, not very 



common. 

 R. Beanii Hanley. — Also from the deep water ; not rare. 

 R. punctura Mont. — With the above; abundant. 

 R. Zetland ica Mont. — This rare and very pretty shell was 



found sparingly in the same habitat as the preceding. 

 R. COStata Mont. — With the above ; not rare. 

 R. parva DaCosta. — All round the shores, and from the deep 



water, every shape and size. 

 R. parva var. interrupta DaCosta. — Sandy shores, and in 



Crow Sound dredgings, never from deep water. 

 R. membranacea Ads. — Very abundant on Zostera beds with 



Trochus striatus and Littorina obtusata. 

 R. striata Ads. — Common everywhere, low water mark to 40 



fms. 



J.C, iv., April, 1885. 



