   The '''Chambered Nautilus''', '''''Nautilus pompilius''''', is the best-known species of nautilus. The shell, when cut away reveals a lining of lustrous nacre and displays a nearly perfect equiangular spiral.  The shell exhibits countershading, being light on the bottom and dark on top. This is to help avoid predators because when seen from above, it blends in with the darkness of the sea, and when seen from below, it blends in with the light coming from above.  The chambered nautilus has more primitive eyes than some other cephalopods; the eye has no lens and thus is comparable to a pinhole camera. The species has about 90 tentacles with no suckers, which is also different from other cephalopods. Chambered nautiluses have a pair of rhinophores, which detect chemicals, and use olfaction and chemotaxis in order to find their food.  The oldest fossils of the species are known from Early Pleistocene sediments deposited off the coast of Luzon in the Philippines.   ==Subspecies==  Two subspecies of ''N. pompilius'' have been described:  * ''Nautilus pompilius pompilius'' * ''Nautilus pompilius suluensis''  ''N. p. pompilius'' is by far the most common and widespread of all nautiluses. It is sometimes called the '''Emperor Nautilus''' due to its large size. The distribution of ''N. p. pompilius'' covers the Andaman Sea east to Fiji and southern Japan south to the Great Barrier Reef. Exceptionally large specimens with a shell diameter of up to 268&amp;nbsp;mm[ ''Nautilus repertus'' ID:118764]. Shell Encyclopedia, Conchology, Inc. have been recorded from Indonesia and northern Australia. This giant form was described as '''''Nautilus repertus''''', however most scientists do not consider it a separate species.  ''N. p. suluensis'' is a much smaller animal, restricted to the Sulu Sea in the southwestern Philippines, after which it is named.  The largest recorded specimen measured 148&amp;nbsp;mm in shell diameter.  == In literature and art == 16th century [[Northern Mannerist nautilus cup]] Nautilus shells were popular items in the Renaissance cabinet of curiosities and were often mounted by goldsmiths on a thin stem to make extravagant '''nautilus shell cups''', like the Burghley Nef, mainly intended as decorations rather than for use.  Small natural history collections were common in mid-19th century Victorian homes, and chambered nautilus shells were popular decorations.  The Chambered Nautilus is the title and subject of a poem by Oliver Wendell Holmes, in which he admires the &quot;ship of pearl&quot; and the &quot;silent toil/That spread his lustrous coil/Still, as the spiral grew/He left the past year's dwelling for the new.&quot; He finds in the mysterious life and death of the nautilus strong inspiration for his own life and spiritual growth. He concludes:  :''Build thee more stately mansions, O my soul,'' :''As the swift seasons roll!'' :''Leave thy low-vaulted past!'' :''Let each new temple, nobler than the last,'' :''Shut thee from heaven with a dome more vast,'' :''Till thou at length art free,'' :''Leaving thine outgrown shell by life's unresting sea!''  A painting by Andrew Wyeth, entitled &quot;Chambered Nautilus,&quot; shows a woman in a canopied bed; the composition and proportions of the bed and the window behind it mirror those of a chambered nautilus lying on a nearby table.  The popular Russian rock band Nautilus Pompilius (Наутилус Помпилиус) is named after the Chambered Nautilus.  American composer and commentator Deems Taylor wrote a cantata entitled ''The Chambered Nautilus'' in 1916.   Cutaway of a nautilus shell showing the chambers Empty nautilus shell, whole Nautilus showing the tentacles Internal anatomy of ''Nautilus pompilius''   