204 R. B. Newton — On the Genus LeveiUia. 



which often bears strong callosities on its inner margins. The 

 continuous fissure is not, however, a persistent character, sometimes 

 consisting of a regular series of isolated perforations, as in Tremanotus 

 of Hall ; in other species the central part of the dorsal area may be 

 keeled or form a mere depression without apparently any connexion 

 with the interior of the shell, until the lip is reached, when a deep 

 notch is usually present. Pleurotomaria, especially its more depressed 

 forms, i.e. P. mirnhilis, Deslongchamps, presents more striking 

 resemblances to our genus. The whole of the Pleurotomariidse 

 possess an uninterrupted slit, its position on the test vai'ying 

 greatly in different species. The P. mirabilis differs from LeveiUia in 

 being subdiscoidal and having a wide band excentrally situated, but 

 its surface ornament is very similar in structure and arrangement. 



De Koninck,^ in his latest review of this genus, ranked it with 

 the Haliotidae, a family peculiar for shells bearing a regularly 

 arranged series of siphonal openings on the dorsum. With this 

 determination I am unable to agree, as the continuous slit or 

 groove is decidedly a feature of much importance in our genus. 

 The evidence would seem to justify us in uniting LeveiUia with 

 the Pleurotomariidse, thus following the views first adopted by Dr. 

 Ferd. Stoliczka^ in 1868, afterwards by Mr, E. Etheridge, jun.,^ in 

 1878, and Dr, Paul Fischer* in 1885, As Leneillia and Bellerophon 

 have usually been considered ta belong to the same family, viz. 

 the BellerophontidEe, it may not be out of place to examine the 

 systematic position of the genus Bellerophon as now understood, 

 it having been, at all times, a question of much dispute among 

 Conchologists, This genus was first established by De Montfort ^ 

 in 1808, and classed under the Cephalopoda. 



De Blainvilles in 1825, followed by John Fleming^ in 1828, 

 regarded it as a Tectibranchiate Gasteropod, and placed it in close 

 proximity to Bulla and Actceon: but the peculiarities of these shells 

 were so very obvious that this grouping never received much 

 support. Deshayes,^ in 1830, placed it with the Nucleobranchiata 

 (Heteropoda), and this view has been more generally received than 

 any other, though it seems somewhat anomalous when one con- 

 siders the delicately formed and small shells of this group, their 

 thin and transparent nature, and the invariable presence of an 

 operculum. It may be observed that no operculum has yet been 

 found in association with either Bellerophon or LeveiUia. De Koninck's 

 researches of 1843 led him to place both these genera among the 

 Prosobranchiates, between Capulus and Pleurotomaria. The Belle- 

 rophontidse were established by Professor M'Coy,^ in 1852, as a 

 family of Cephalopoda for the reception of Bellerophon only. Later, 

 in 1855, in a further fasciculus of the same work (p. 558), LeveiUia 



1 loc. cit. p. 10, 8 Man, Malacology, 1825, p. 477, 



^ Gasteropoda, Mem, Geol, Surv, India, ' Hist, British Animals, 1828, p. 338, 



1868, p. 381, 8 Eucycl. Methodique (vers), 1830, toI, i, 

 3 Cat. Australian Fossils, 1878, p, 87, p. 133, 



* Man, Conchyliologie, 1885, p. 848. » Syst, Desc, British Pal. Foss. 1852, 

 6 Conchyl. Syst. 1808, vol. i, p, 51. p. 307. 



