* Total volume of 3,160 contracts was lowest in 7-1/2 months, but heavier than during the same holiday trading session a year ago. * March canola futures lost 10 cents to $515.00 a tonne on light volume of 1,501 contracts. * May futures lost 10 cents to $519.10 on volume of 852 contracts. * May-July was most active spread, trading 584 times, settling at a July premium of $2.60. * MATIF February rapeseed slipped slightly. * The Canadian dollar was trading at $1.0177 against the US dollar or 98.26 US cents at 1:15 p.m. CST (1915 GMT), up from the currency's North American finish on Friday at C$1.0227 per US dollar, or 97.78 US cents. * Little rain this week for parched Argentine corn.