45 



Genus 1. CYMBIUM, Be Montford. 



Animal ; disc large and muscular capable of considerable expansion, 

 head furnished with an obtuse trunk, tentacles short, broad, 

 dilated at the base into two lobes ; respiratory siphon short, stout. 



Shell ; oblong-ovate, very large, thin and ventricose, whorls elevated 

 around the spire, which is papillary and sunken, with the summit 

 sometimes coronated, sometimes concavely flattened ; plaits of 

 the columella strongly developed, the loioer being the larger. 



The present genus was founded by De Montford, under the name of 

 Cymhium, for the reception of that portion of the Volutes commonly known 

 to collectors by the term ' Melons \ and which Lamarck distinguished as a 

 particular section of his genus Voluta, under the sub-title of 'Les Gon- 

 doHeres/ The generic arrangement of this group has, however, been a 

 matter of some difference of opinion; for whdst M. Deshayes considers 

 the adoption of Cpnh'mm, as a genus of the same ranJk with the Valuta 

 proper, quite uncalled for, on account of the similarity of the animals ; 

 Mr. Broderip and Mr. Sowerby have still fui'ther divided it into Cpnha 

 and Melo, for the sake of observing a generic distinction between the 

 coronated and the flattened species. After weighing the merits of these 

 opinions, I propose to take the middle course, and return to the method 

 originally introduced by De Montford, of including both varieties of 

 ' Melons ' under the same head. 



The animal of Cymbium varies to a certain extent from that of Voluta in 

 the size and extensive muscular expansion of the disk ; the shells are, more- 

 over, distinguished by their light inflated growth, and sunken papillary spire, 

 around which the whorls are elevated, with their summit sometimes con- 

 cavely flattened, sometimes coronated with a diadem of vaulted scales. 



One or two species of Cymhium are found in Australia, but the chief portion 

 are from the coast of Africa ; they burrow in the sand at low water, and 

 Hve mostly concealed from view. 



Species. 



1. ^tliiopicum, Brod. 7. Indicum {Vol.), Gmel. 13. patukim, Brod. 



2. armatum {Vol.), Lam. 8. Linnsei, Reeve. 14. porcina {Vol.), Lam. 



3. Broderipii, Grai/. 9. Miltonis {Vol.), Men. 15. proboscidale {Vol.), L. 



4. diadema {Vol.), Lam. 10. nauticum {Vol.), Lam. 16. rubiginosum {Vol.), S. 



5. ducale {Vol.), Lam. 11. Neptuni {Vol.), Lam. 17. tessellatuin, Brod. 



6. gracile, Brod. 12. oUa {Vol.), Linn. 18. Tritonis, Brod. 



