This is a close relative of Akantharges mbareki but the Akantharges is more ornate. In particular, if you look at the upper edge of rear of the pygidium the Basseiarges has a row of bumps while the Arkantharges has a sequence of deep indentations and prominent knobs. These two trilobites should probably have been made different species in the same genus.
In addition to viewing the images on this page, you have the option to download the detailed (and large) image files, or to display the detailed files in your browser. (Refer to the buttons below each image.)