olympus xD card will not fit sd slot

I have just got my mac pro. Never had an apple before. Taking a bit of getting used to. I am wanting to transfer photos from my olympus digital camera to my mac and then to facebook etc but appears the sd slot will not take my xD card????? Seems right size and will go part way in at an angle but will not just slide right in? I have used this xD card in numerous other laptops, but never tried on a mac before. Hoping I do not need to other cable or device.