272 MR. E. A. SMITH ON THE [-^P''. 1, 



Ianthina exigua, Lamarck. 



Hab. South Atlantic ; " New Zealand, New South Wales, and 

 S. Australia" {Button). 



I have compared New-Zealand specimens in the Museum with 

 the one from St. Helena, and can discover no distinction. 



Ianthina umbilicata, d'Orbigny. 



Ianthina umbilicata, d'Orb. Sagra's Hist. Cuba, Alollusq. vol. ii. 

 p. 85, Atlas, pi. XX. figs. 22, 23 (bad !) ; id. Voy. Amer. Merid. 

 vol. V. p. 414; Reeve, Con. Icon. figs. 22 a, b ; Sowerby, The- 

 saurus, pi. 444. fig. 22. 



Testa parva, violacea, infra suturam albo anguste zonata, anguste 

 perforata ; anfractus 5, primi duo (nucleus) obliqui, pnrvi, 

 papilliformes, pellucidi, cceteri convexi, nitidi, ultimus in medio 

 obtuse anyulatus et sulcatus, incrementi lineis, in medio angtt- 

 latis, sculptus ; apertura mediocris, inferne anguste effusn ,• 

 columella rectiuscula, paulo reflexa ; labrum profunde et acute 

 incisum. 



Alt. 9? milliin., diam. 8. 



The British Museum received many specimens of this species 

 from Mr, Nuttall in the year 1855, under the name of I. bifida^. 

 They were obtained at the Sandwich Islands. The shell figured by 

 Keeve under that name is altogether different, and seems to me but 

 a form of /. exigua, as suggested by Sowerby. Besides the lines of 

 growth, which are perhaps a trifle coarser on the under surface than 

 upon the spire, there are indications of feeble spiral striae, chiefly 

 upon the base. 



The figure given by d'Orbigny is not good, and does not accord 

 with his description. The labrum is described as acutely sinuated, 

 and the surface as smooth, or scarcely marked with faint lines of 

 growth, yet the figure depicts no sinuatiou, but represents rather 

 well-marked incremental striae. In d'Orbigny's South-American 

 shells are preserved three or four specimens of this species, marked 

 /. umbilicata in his own handwriting. These certain!}' agree with 

 the single specimen from St. Helena and the large series from the 

 Sandwich Islands. The figure in Reeve's ' Conchologia ' represents 

 the form correctly, but does not show the deep labral notch. 

 D'Orbigny describes the colour as uniform deep blue, but his 

 specimens have the pale iufrasutural line as described above. 



All the specimens of this species which I have examined are of 

 small size, none exceeding the dimensions above given. 



Ianthina pallida, Harvey. 



Hab. Ireland (Thompson) ; Straits of Magellan (Jeffreys). 



The single St. Helena specimen, half an inch in length, agrees 

 very closely with Forbes and Hanlev's figure (Brit. Moll. pi. 69. 

 figs. 10, 11). 



1 Blanford, ' Geology and Zoology of Abyssinia,' p. 463, gives olf tlie S.E. 

 coast of Arabia as a locality for this species. 



