James Hall

“ Carapace broadly semi-oval or semi-circular; length more than two-thirds the width; margin distinctly limited. Eyes situated on a line across the middle of the length of the carapace and distant about one-fourth the breadth from the margin.
Abdomen wide to the seventh segment, then abruptly narrowed and gradually decreasing in width to the telson. The first somite is anchylosed to the carapace. The widest part of the body is across the fourth segment, which is more than three times the width of the last one. ”

“ Body elongate, very convex along the dorsum, composed of twelve free segments which gradually increase in breadth from the head backwards to the fifth somite, from whence they rapidly decrease in width and increase in length, until the eleventh segment has a length equal to half its width, while in the fifth segment the breadth is four times its length. ”

“ Midway between the eyes is a small flat node or elevation, on each side of which is a larger longitudinal prominence. There are also two similar nodes above the posterior margin. The posterior angles show two oblique short ridges. These elevations of the carapace probably indicate the positions of internal organs and the points of attachment of muscles.
The surface ornaments are not well-preserved, the specimen shows numerous small tubercles, especially over the posterior portion.
The carapace has a length of 8.5 mm. and a breadth of 15 mm. ”