I recently purchased a specimen which I thought was going to be Clytosaurus priapus Thomson; and of course when it arrived it was a beautiful specimen of C. siamensis from Vietnam.
However, in examining my material I found a few specimens from Cameron Highlands, Malaysia which are very different from typical C. siamensis;
Only two pronotal crescents, legs all black; antennae all black, transverse carina on the pronotum very short.
They are clearly different. Same genus? (left specimen from Malaysia (ID'd as Clytosaurus siamensis by a recognized expert), right specimen from Vietnam).