II.—On Necrozius Bowerbankii, a new Genus of Canceridæ from the London Clay

Abstract

On the genus Necrosius.—This new genus is very near to Ozius, and is still more near to a small genus, established a few years since by M. Stimpson, named Spherozius. Like this last-named form, the carapace of Necrozius is remarkable for its globular form, its width scarcely surpassing its length. The curve of the buckler is slight in a transverse direction, but is great from back to front, the anterior border being much curved down. The latero-anterior borders are continuous, almost without interruption, with the latero-posterior, which latter are swollen. The frontal border (rostrum) projects a little, and is slightly depressed in the centre. The basal joint of the internal antennæ is large, and it is articulated obliquely beneath the front (rostrum). The basal joint of the external antennæ is short, not reaching to the front as in the Pseudozius of Dana, and in spherozius of Stimpson; the articulation is free and is not lodged in the internal obital cavity. With Ozius on the contrary, this basal joint is fully attached to the front.