NOTE ON HALIOTIS SIEBOLDII, REEVE. 



By E. A. Smith, I.S.O. 



Read Uth November, 1913. 



The unique specimen described hj K.eeve ' as Haliotis sieholdii lias 

 been ie<>'arded by tbe monographers Sowerby,^ Weinkauff,^ and 

 Pilsbry/ merely as a probable monstrosity of the Haliotis gigantea 

 of Chemnitz as that species was defined by Deshayes ^ and is now 

 understood. 



A second, much larger specimen, has been presented to the Eritish 

 Museum by Mr. Henry Harvey, to whom the Museum has been 

 indebted for many remarkable conchological abnormalities, and also 

 for nearly all the tj'pes and figured specimens contained in the 

 Sylvanus Hanley Collection. 



The shell in question unfortunately has been denuded of its outer 

 coating, so that only the pearly structure remains. The form, 

 however, is practically identical with tliat of the type as depicted 

 by Reeve, showing every appearance of regularity in its growth, 

 and therefore I am inclined to regard these two specimens, not as 

 abnormalities, but as representatives, either of a distinct species, or, 

 at all events, of a local variatioTi of the Chemnitzian shell. 



A remarkable feature of IT. sieboldii, besides its characteristic 

 convex shape, is the almost marginal ])osition of the spire. This, in 

 the type, is rather eroded, but appears to have been almost on the 

 margin, coiling away from it but very little. In Mr. Harvey's 

 larger specimen it is more evident, the apex being at a distance of 

 13 ram. from the edge of the peristome. 



Excepting towards the spire, the curve of the line of perforations 

 is very slight as shown in Reeve's figures, whereas in typical examples 

 of TI. gigantea the curve is conspicuous, and the apex of tbe spire in 

 a sliell of the same size is from 25 to 30 ram. from the margin. Both 

 examples of H. sieholdii are strongly radiately costate, so that the 

 peristome is conspicuously frilled and the interior deeplv sulcate. 



The larger shell is 170 mm. in length, 125 in diameter, and 55 

 in depth. 



' Concb. Iconica, vol. iii, figs. 'i'2a-h. 



" Thesaurus Conch., vol. v, p. 18, pi. 437, fig. 72. 



■' Conchylien-Cab., p. 80, pi. xxx, fig. 1. 



"* Man. Conch., vol. xii, p. 85, pi. xv, figs. 78, 79. 



* Lamarck's Aniin. sans Vert., 2nd ed., vol. ix, p. 24. 



