Nymphs have a distinctive "rhino horn" behind the eye not found in Banded Demoiselle nymphs. 

Banded Demoiselle

The Beautiful Demoiselle favours fast flowing streams with clean stony or sandy beds.

Rare vagrant in Leicestershire and Rutland.

Although cited historically by various authorities as being "common on the Southern boundary (of Leicestershire) and in Rutland" (Roebuck, 1932), "locally common (in Leicestershire)" (Longfield, 1937) and present in Leicestershire in 1960 (Corbet et al, 1960), there were no recent records of this species in VC55. There were just four records on the Leicestershire and Rutland Dragonfly Group (LRDG) database, the most last in 1973. 

It now appears to be spreading into the southern part of VC55.