26 TOxMLIN; NOTES ON MARINE MOLLUSCA OF NORTH WALES. 



species. For instance, Cylichna alba Brown is a deep-water 

 rarity from the Shetlands, and cannot occur at Barmouth. 

 Donax trunculiis L., again, is recorded from four localities, 

 whilst D. vittatus L. is queried from one. As D. truncithis is 

 only admitted by Jeffreys into the British list on the strength of 

 two Devonshire specimens, we may .safely refer all the W'elsh 

 records to D. vittatus L. { = anatinus Lam.). A good deal of 

 confusion originated with Forbes and Hanley, who included 

 both vittatus and trunculus in their D. anatiuus. Possibly 

 Mr. Greene's doubtful record should read D. politus. We may 

 also be allowed to doubt the correct allocation of Pectcn varius 

 van nivea Macg., an exclusively northern form, very different 

 from the ordinary white varius and sometimes considered a 

 distinct species : and of Chiton albus L. The following are 

 nearly all supplementary to Mr. Greene's list, and, except where 

 otherwise specified, of littoral occurrence. Records initialled 

 'F. A.' are on the authority of Mr. F. Archer, of Liverpool: — 



Anomia ephippium var. squamula L. — Common on roots 

 of Lauiiuaria wherever washed up. 



Pecten pusio L. — Valves at I'enmaenmawr. Alive, Car- 

 narvon Bay (F.A.). 



Modiolaria discors L. — Occurs commonly at the routs of 

 Lamiuaria and Corailiua passim, from Barmouth to 

 Criccieth. 



Lepton squamosum Mtg. — Anglesea (Jeff.) Valves are not 

 uncommon all over the area of the Liverpool Marine Bio- 

 logical Committee. 

 . Montacuta bidentata Mtg. — L found a perfect specimen 

 among some drift from Rhyl. 



Cardium nodosum Turt— Dead at Bull Bay, Anglesea 

 (F.A). 



Venus fasciata DaC. — Formerly rather plentiful at Llan- 

 dudno. 1 have not taken it there for several years now. 



Venus ovata Penn. — Bull Bay (F.A.), generally dead. 



].(':. \ii.. Jan.. rHo'j, 



