Roy J. Snell (1878-1959) authored at least 85 Young Adult novels under his own name and as by David O\'Hara, James Craig, and Joseph Marino, most of them specifically directed to boys, though he wrote at least one series of mysteries for girls. His tales for younger children, beginning with Little White Fox and his Arctic Friends (1916), are animal Fantasies.
The Four Legendary Kingdoms
Only a Mother
The Last Dance
No Body
Movie Menace
Judith Alguire - Rudley 04 - Peril at the Pleasant
Hostage Run
Water-Ski Wipeout