I realize this isn't a weighty issue for anyone, but I am hoping 
someone will take the trouble to explain something that I've been 
wondering about for some time.  My favorite editions of Tom Sawyer are 
from Heritage Press.  I have several copies.  I like the Rockwell 
illustrations.  I've noticed that the title pages sometimes read "The 
Adventures of Tom Sawyer" by Mark Twain, while in other copies it 
reads, Samuel L. Clemens "The Adventures of Tom Sawyer" ......... no 
mention of Mark Twain anywhere.  Can someone tell me why the 
difference?  I have noticed older editions of other works of Twain 
occasionally using the Clemens name instead of Twain, and assumed this 
was a publisher trying to get around paying royalties or an estate 
thing with Twain's heirs, but why the same publisher would use both 
names in different print runs I can't understand.

Thanks,
Jerry