This is a vintage-style illustration featuring two horseflies perched on a rough, light-colored stone or rock face. The flies are depicted with detailed wings and bodies, showcasing their segmented structure. They appear to be resting on thin blades of grass and other small plants growing around the base of the stone. The background is a soft, muted yellow, giving the image an aged, antique feel. The style is reminiscent of scientific illustration, with a focus on accurate depiction of the insects and their environment. There's a signature or initials 'CD' in the lower left corner.