Abstract
Amphicteis midas and A. gunneri are redescribed from British and North Sea material including the types of A. gunneri. The two species have long been confused under the name A. gunneri but are readily distinguished morphologically and appear to be separated ecologically. Amphicteis midas was only found in shallow < 30 m) waters including the intertidal whilst A. gunneri was restricted to deeper waters. On the basis of an examination of limited material from other areas, it was concluded that the cosmopolitan status of A. gunneri is unjustified.