Books like Shells
S. Peter Dance, DK Publishing
Shells is 256 pages, about 4 hours 42 minutes at 250 words a minute.
6 books to read next
How long each takes
Sharing a Shell 30 min 
Dr.Seuss's Fabulous Fables 3.2 h 
Cars, Trucks and Things That Go 1.3 h 
I Wonder Why Camels Have Humps 35 min 
Nasty Nature 2.9 h 
Animalium 1.5 h Bar height shows length. Estimated at 250 words a minute.