NAUTILUS. iN 
Mautilus rugosus. 
No additional particulars have been communicated in the 
revised copy so often alluded to; nor did Linneus possess this 
species, which, as Dillwyn remarks, has not apparently been 
recognised by any subsequent writer. The brief description, in 
the absence of any illustrating reference, is utterly inadequate 
for the purposes of definition. Hence this species must be 
reckoned among the irrecognisable. 
PMautilus wobilicatis. 
Nothing is added in the revised copy to the published de- 
scription. The species is not the Nautilus wmbilicatus of Sow- 
erby, which is a true Nautilus, but is one of the Foraminifera. 
No additional information respecting it is to be found in Schro- 
ter, Gmelin, Dillwyn, or Lamarck. Columna’s figure seems to 
harmonise fairly enough with the description of Linneus ; if, 
then, it should be considered a recognisable one, and examples 
should be found which agree with both that engraving and the 
words of our author, they may be regarded as representatives of 
the Linnean species; if, on the contrary, they suit the draw- 
ing, but are at variance with the diagnosis, the wmbilicatus must 
be held indeterminable. As the work referred to is not com- 
mon in our libraries, 1 may remark that the drawing is like 
figure 10, P. of the first plate of Plancus (Conch. Min. Not.), 
but exhibits a decided umbilical hollow. 
Pautilus spirula, 
The specimens (List. Conch. pl. 550, f. 2) in the Linnean 
cabinet which alone agree with the definition belong to the 
Spirula Peronw of the Lamarckian System. Whatever may be 
the differences in the animals of Spirula (of which three species 
are now enumerated), no constant differential features have 
