This is one of those tiny tidbits that some of you may know and some might not but here it goes. Do you know the difference between a coffin, casket and sarcophagus?
A Coffin is wider at the shoulders, narrower at the head and feet.
A Casket is a simple rectangle.
A Sarcophagus is the shape of a human body and often has the portrait of the deceased painted on the top.
On another note: Coffin seems to be the word of choice for the first half of the 19th century. Whereas, casket came into use, first time attested to in 1849. However, I'm seeing more use of the word casket in the later part of the century.