278 
XAUTILOIDEA. 
Remarlcs. As no mention is made of this species by d’Orbigny in 
bis ‘ Prodrome ’ or elsewhere, it may be assumed that be never 
succeeded in obtaining such material as would have enabled him to 
describe the species completely. There is, however, a specimen in 
the British Museum (Xo. 37001) which possesses all the characters 
essential for the diagnosis of the species, which may thus be de- 
scribed : — Shell somewhat inflated, sides and periphery rather 
flattened, thus giving a squarish form to the whorls in section ; 
widest part of the whorls in the umbilical region. Umbilicus open, 
of moderate size. Septa moderately distant ; sutures considerably 
Nautilus elegantoides. — a, lateral riew of a very imperfect specimen, showing 
the form of the sutures ; b, front view, showing the position of the 
siphuncle. Drawn from a specimen in the British Museum. One third 
natural size. 
curved backwards on the sides of the shell and forming a con- 
spicuous sinus on the periphery. Siphuncle considerably below the 
centre of the septa. Ornaments (seen only on the cast) consisting 
of strong, prominent, transverse ribs, which often separate iuto 
bundles of from two to four after leaving the umbilicus, so that in 
the latter situation they are much wider and coarser than in any 
other part of the shell. The interspaces dividing the ribs do not 
exceed one half the width of the latter. The ribs are only slightly 
