Ceratinostoma ostiorum (Haliday in Curtis, 1832)

A large, robust, dark grey, sea coast species. The whole fly is covered in dense dark grey dusting, with some brown areas on top of the thorax. Frons also rather dark blackish-brown. Only on the rather stout proboscis does the black ground colour show. Palps yellow-brown, conspicuously long and armed with rather stout, short black bristles. Legs entirely grey dusted, but the undersides of the tarsi are covered in a thick felty layer of yellowish-brown hairs. Wing length: ♂ 4.5 - 6.7 - 7.7 mm (16); ♀ 5.1 - 6.4 - 6.9 mm (6).