396 SPECIES OF THE SYSTEMA. 
alike to the brief definition in the ‘Systema’ (and consequently 
should each be quoted as “ Nerita albumen, partim”), yet not 
one of them precisely corresponds with the details specified in 
the ‘Museum Ulrice’ (where, by-the-bye, “subglobosa” re- 
placed ‘‘ convexa,” and no mention was made of the peculiar 
lobe), an arbitrary selection became almost inevitable, if the 
name was to be preserved at all in our catalogues. ‘The 
majority of conchologists have preferred to retain the appella- 
tion for the shell delineated by Rumphius, and assuredly the 
original distinctive characteristics of simple convexity and flat- 
ness of lobe are preeminently developed in that species (Natica 
albumen of Lamarck); moreover, the “ Vitellus compressus” of 
the Dutch naturalist suggested, in all probability, the specific 
epithet. 
evita manimiella, 
So many very similar shells, formerly regarded as at most 
varietal forms of a common and widely diffused species (the 
Natica mammilla cf authors), have been distinguished, of late, 
as essentially distinct, that it becomes desirable to ascertain 
which of them, and upon what grounds, is best entitled to the 
original appellation. It is manifest from the expressions used 
relative to an umbilicus in both the ‘ Systema’ and the ‘ Museum 
Ulrice,’ as well as from the ‘‘lactea aut lutea” of the latter 
publication, that Linneus admitted of so wide a range of varia- 
tion, that even had a marked example of mammilla been pre- 
served in his cabinet, it would not have decided the question. 
Divers Natice are referred to in the synonymy; yet the 
majority of the cited figures (although, from the rudeness of 
their execution, and the circumstance that many of them are 
only dorsal views, it would be bold to decide respecting them) 
appears to be intended for the common imperforated snow- 
white Oriental shell (Chemn. Conch. Cab. v. pl. 189, f. 1928, 1929) 
which had been known by the equivalent epithet ‘‘ mamma” and 
“mammelon blanc” long previously to the publication of the 
‘Systema.’ The early and general acceptance of that species 
(numerous individuals of which are present in the Linnean 
collection) seems to have been based upon these grounds, and 
