276 
NAUTILOIDEA. 
for d’Orbigny’s type ; and remarks that “ if X elerjans^ d'Orbigny, 
is specifically distinct from the previously published X. eJecjans^ 
Sowerby (which seems very probable), of course d'Orbigny’s shell 
will have to receive some other name, as two species of the same 
genus cannot retain the same name.” The required name has, as 
we have seen, been supplied by Mr. Whiteaves. 
Judging by Meek’s careful description and admirable figures of 
the American form, it appears to me to be distinct from N. elegans, 
Sowerby, as now redefined from the original specimen, and also from 
d’Orbigny’s and Sharpe's N. degans^ wliicli have been re-named 
X. Atlas. While admitting that Meek’s form has undoubted affini- 
ties with the last-named species, I find that it differs in having a 
much wider shell, an open though small umbilicus, at least in the 
adult, and the siphuncle somewhat nearer the centre. On the 
whole, it is more like the Indian form already mentioned than the 
French form, X. Atlas. 
Eegarding Meek’s form — X. elegans, var. Xthrascensis — ^fr. Whit- 
eaves 1 expresses the following opinion : — that “ the description of 
the Nebraska fossil . . . .accords much better with that of X. Atlas 
(nobis) than with Sowerby’s diagnosis of his X. elcgans. The 
globose shape, together with the position of the siphuncle in the 
American shell, are in favour of this view ; but it is possible that the 
varietal name, proposed by Mr. Meek, may have to be raised to 
specific rank, as the sculpture of the so-called ‘ variety Aebrasceyisis’ 
is said to consist of ribs which are ‘ five i imes as broad as the grooves 
between,’ and in this respect it differs from iV. Atlas., as well as 
from allied species.” 
. It is due to Mr, Whiteaves to observe that he arrived at the con- 
clusion, from a careful study of the descriptions of the species, that 
the Nautilus elegans of d’Orbigny and of Sharpe was distinct from 
the X. elegans of Sowerby, before he was aware that Pictet^ had 
already pointed this out. 
Upon the American species of Cretaceous Nautili, Mr. Whiteaves 
remarks : — “ The few Nautili of the section Iladiati, which have yet 
been described or quoted as occurring in the Cretaceous rocks of the 
United States, present ' curiously close affinities with European 
species.” ® 
English specimens of Nautilus elegans are frequently in a crushed 
^ Geol. Surv. of Canada— Mesozoic Fossils, 1876, vol. i. pt. i. p. 18. 
^ Descr. des Foss, du Terr. Oret. des Environs de Sainte-Croix (Pal. Suisse), 
ser. ii. pt. i. 1859, p. 117. 
^ Ceol. Surv. of Canada — Mesozoic Fossils, 1876, vol. i. pt. i. p. 17. 
