We present the first comprehensive catalogue of variable stars in the Leo II dwarf spheroidal galaxy .
We have identified 148 RR Lyrae type variables , of which 140 were amenable to derivation of variability parameters with our data .
We have also confirmed the existence of four anomalous Cepheids as identified in previous studies .

The average period of the RR Lyrae ab variables ( 0.62 days ) , the fraction of c variables ( 0.24 ) and the minimum period of the RR Lyrae ab variables ( 0.51 days ) all define Leo II as an “ Oosterhoff intermediate ” galaxy .
We have used the properties of these variables to derive a metallicity for Leo II of approximately [ Fe/H ] =-1.9 .
We attempt to resolve discrepancies between this value and those determined by previous efforts .
The presence of longer period , higher amplitude RR Lyrae variable implies a metallicity distribution that extends to as poor as [ Fe/H ] =-2.3 .

Leo II ’ s location on the period-metallicity relation of clusters , like that of other “ Ootershoff intermediate ” objects , falls between the Oosterhoff Class I and Oosterhoff Class II clusters .
The properties of the variable populations of these objects are consistent with the idea that the Oosterhoff “ dichotomy ” is a continuum .
The gap between the classes seems to be explained by the horizontal branch of Galactic globular clusters shifting away from the instability strip at at intermediate metallicities .
However , Leo II , as well as other Oosterhoff intermediate objects , has a second parameter effect strong enough to leave horizontal branch stars in the instability strip .