MARSHALL: ADDITIONS TO " BRITISH CONCHOLOGY." 305 



while other collectors have been even less successful. At Mr. Gal- 

 lienne's death I noticed in his collection a box containing many 

 specimens. Its old neighbour, however, P. rufa var. lactea, still lives 

 in the bay, as I have frequently found it there. 



During a recent visit which I paid to Guernsey, a final search 

 among the miscellaneous stores in the Guernsey Museum brought to 

 light the above-mentioned identical box with the specimens still in it, 

 which enabled a fine series to be mounted and placed in the Museum 

 collection. . . 



An intermediate form lives in gravelly sand at low-water mark in 

 Torbay, also at Jersey, Guernsey, Caldy Island, and Connemara. It 

 is four lines in length and proportionally as broad as the type, with a 

 shorter spire, longer body-whorl, and the typical sutural rim. It is a 

 small type-shell rather than a large varietal one, and lives with the 

 type in Guernsey and with the variety in Jersey. A monstrosity of 

 this form from Jersey has a varicose rib on the last whorl, and the 

 animal has thence started on a fresh growth and developed a body- 

 whorl equal in size to the type. Jeffreys gives a good figure, and so 

 does Sowerby, but that of the latter is the var. minor. 



Forbes and Hanley described and figured the small form of this as 

 P. nebula var. Icevigata^ and Canon Norman has bestowed on the 

 large form the name oi P. nebula var. vittata ;^ but the latter is quite 

 superfluous, P. Icevigata being as distinct as any other member of the 

 genus. It is true Philippi described the minor form as the type, the 

 major one being unknown to him, and Gwyn Jeffreys' freedom to 

 transpose the two forms may be open to argument (it would perhaps 

 have simplified matters had he named the Guernsey form var. major); 

 but as a matter of fact P. Icevigata and var. minor differ only in size, 

 the "strap-like rim" of Gwyn Jeffreys, or the "fillet passing round 

 the summit of each whorl" of Canon Norman, being common to all 

 three forms I am treating of, though not present in all specimens. 

 This character is consequent on the top of each whorl being welded 

 on the periphery of the preceding one, which is so striking a feature in 

 the common Mediterranean species Euthria cornea L., though there 

 again it is not present in all specimens. Another character in which 

 P. IcBvigata differs from P. nebula is in the aperture, which is longer 

 and narrower, not inflected, and with a straighter canal, well exempli- 

 fied in the figures of each given by Forbes and Hanley and by 

 Sowerby. From a description left by Gwyn Jeffreys in his MS. notes, 

 the animal of the var. minor does not differ from that of the type.^ 



1 Brit. Moll., vol. iii., pp. 467-80 ; and vol. iv., pi. cxiv., fig. 8. 



2 Ann. Mag. N. Hist., i8gg, vol. iv., p. 135. 



3 Moll. 'Porcupine' Exp., Proc. Malac. Soc, 1906, p. 189. 



