In LLPSI Pars II: Roma Aeterna Orberg scribit:
Postremus siccatus est locus in medio foro qui 'lacus Curtius' dicitur a nomine equitis cuiusdam qui se armatum cum equo suo in voraginem ibi factam praecipitavisse narratur.
...post 'cuiusdam'.
..qui se armatum (who armed) cum equo suo (with his horse into a hole that had appeared / happened -'factam' <--> 'voraginem') there, was said to have fallen.
Cur 'se'? Eques in voraginem equitavisse voluerat?
Necessarius est 'se'?