The shell is circular or oval in outline, and reaches a maximum length of approx. 10 mm. The external surfaces are smooth except for fine concentric growth lines. The shell is endopunctate and yellowish-white in colour. The pedicle foramen is elongate, and the deltidial plates do not join medianly. The ventral umbo is slightly incurved.
It has a long loop attached to a median septum (G. spitzbergensis internal).
In British waters it is found in depths between 70 and 700 metres.
It has a circum-Arctic distribution, having been found off Iceland, the Faeroes, Norway, Shetlands, Spitzbergen, arctic Canada and Japan. It has also been found around the Scilly Isles.