The Buffet Apogee
These relatively uncommon horns (primarily because they were over 20% more expensive than other Buffet models that didn't have all of the additional keywork) were an improvement and extension over the "Evette-Schaeffer System" models that were introduced in 1887.
This odd keywork served as the inspiration for the Holton Rudy Wiedoeft model, several models of Beaugnier horns (most famously, the Rationale and Semi-Rationale) and the Allen Loomis prototypes.
See also Paul Cohen's Vintage Saxophones Revisited article in the May/June 1993 issue of the Saxophone Journal magazine.