[Mono-osx] Installed 2.4.2.3 on OSX 10.5 but no "mono" command

[Mojito Sorbet]

I admit to not having touched a Mac since OS8.  I have had no trouble 
with mono on Linux.

I downloaded the Mono 2.4.2.3 CDSK for PowerPC to my G4, and opened the 
dmg file.
That showed me a pkg file, which I opened.
That ran an installer, which it said was successful.
Opened a Terminal, but the "mono" command is unknown.

Am I missing a step?