MARSHALL : ADDITIONS TO BRITISH CONCHOLOGY. I97 



canal is short and open in Purpura, long and closed in Ahirex ; but 

 the closing in of the canal is very gradual, and only complete in aged 

 specimens ; while the sculpture also is that of Purpura, and not 

 Murex. (See Gwyn Jeffreys and Searles Wood, junr., in the Annals 

 for 1883, pp. 66-7, 143, and 20S). 



Although P. hctmnstonia L. has been figured by Gwyn Jeffreys in 

 his Appendix, and by Sowerby in his " Index," its British origin is 

 extremely doubtful. Judge Macculloch's discovery of three specimens 

 at St. Peter's Port, Guernsey, is no doubt quite correct so far as it 

 goes, but the same spot has been searched many times since without 

 confirming its occurrence, and as many French vessels are constantly 

 visiting that port, in all probability these specimens had a French 

 origin. After more than one diligent search, I have been unable to 

 trace these three specimens in the collection of Sir Edgar Macculloch, 

 which came into the hands of the Guernsey Museum on his death in 

 1898. Among Sir Edgar's foreign shells, however, is a tablet con- 

 taining six specimens of this shell, three dead and three live, but as 

 he kept no record of localities, it is impossible to say which three, if 

 any, are of Guernsey origin. 



[My notes on the genera Cassidaria, Bucchiuni, Buccinopsis, Triton, 

 and Fusus were published as a separate paper in the Journal of 

 Malacology for 1902, vol. ix., no. 2. They are now revised and 

 brought up-to-date for insertion in their proper order]. 



Cassidaria tyrrhena Chemn. — Since my account of this species 

 was published ^ Mr. F. W. 'Wotton has received several very fine 

 living specimens which were obtained by trawling off the south-west of 

 Ireland in 5o-6of., two of which he very generously presented to me. 

 His largest specimen measured 3|in. by sjin., and contained the 

 animal still showing signs of life. I have another fine specimen 

 exceeding 3in. by 2in., dead but perfect, trawled in 5of. south of the 

 Scilly Islands, in 1900. It has also been recorded "off the Kerry 

 coast" (Tattersall). A fragment was dredged by the 'Porcupine' 

 Expedition of 1870 on the Channel slope off the Scillies in 539f, 

 and another fragment of C. echinophora by the 1869 expedition off 

 Donegal Bay in i83f 



The Mediterranean form of C. tyrrhena is smaller and thinner 

 than ours, and lives in shallower water. The Irish and Scillonian 

 specimens belong to a larger and coarser deep-water form, which 

 Monterosato calls var. ailantica. 



Mr. E. A. Smith has conclusively shown" that Morio Montf. has 

 the preferential claim for recognition over Cassidaria, if the coleop- 



1 Jourri. Conch., 1893. vol. vii., p. 260, and 1894. p. 380. 



2 Journ. JNIalac, 1B95, vol. iv., p. ti. 



