61 



» Genus 4. EBURNA, Lamarck. 



Animal ; disc stout and thick, oval in front, pointed behind, 

 carrying a horny operculum at the posterior extremity which 

 jits exactly to the aperture of the shell ; head large, bifurcated 

 in front into two elongated tentacles, at the outer base of which 

 are the eyes ; mouth armed with a cylindrical trunk ; respira- 

 tory siphon rather long. 



Shell ; oblong-ovate, spire acuminated, with the sutures more or 

 less deeply channelled ; whorls forming a deep umbilicus which 

 is rarely filled up ; colour ivory white, tessellated and spotted 

 with orange-brown. 



The genus Eburna includes a natural, though extremely limited group 

 of species, but M. Deshayes questions whether it is entitled to rank higher 

 than as a section of Buccinum ; from Ins description of the animal, above 

 recorded, we learn that it has a strong natural affinity with that genus, yet 

 there is a curious peculiarity of design in the structure and colour of the 

 shells. It is not usual to regard colour as an element in the character of 

 a genus, but in the case before us it constitutes a feature which cannot be 

 overlooked. Divested of the E. glabra ta, plumbea, and spirata, which have 

 been erroneously referred to this genus, the species are each distinguished 

 by a blotched and tessellated painting of orange brown upon a white 

 ground, which is very characteristic ; the apex throughout is black, and 

 the columella and interior of the aperture white. 



The E. spirata and Zeylamca are found in Ceylon in great abundance ; 

 the species selected for illustration are from Japan, and of great rarity. 



Species. 



1. ambulacrum, Sow. 4. Japouica, Reeve. 7. Valentiana, Swainson. 



2. areolata, Lam. 5. lutosa, Lam. 8. Zeylamca, Lam. 



3. australis, Soto. 6. papillaris, Sow. 



Figures. 



Eburna papillaris. Plate 4. Fig. 19 a. — From Mr. Cuming's collection. 

 Eburna Japonica. Plate 1. Eig. 19 b. From Mr. Cuming's collection. 



