Borders Project Research Articles

ON A CARBONIFEROUS TRILOBITE FROM ANGRAM, IN NIDDERDALE

Dr. F. A. Bather recently transmitted to me some remains of a small Trilobite from Angram, in Nidderdale, which he had received from Mr. E. Hawkesworth, of Leeds. The fossils are contained in black carbonaceous shales occurring below the Millstone Grit in the Cyathaxonia beds immediately below the Lower Culm, and on the same horizon as those at Bishopston, Glamorganshire, which yielded to Mr. F. Barke, F.G.S., a good example of a new species of Trilobite named Griffithides Barkei (see my paper on “Culm Trilobites”, Geol. Mag., 1902, pp. 484–486, PI. XX., Figs. 14, 15). The Nidderdale black shales contain numerous detached portions of a small Trilobite, a Pecten, and several Brachiopods. The fossil was found during the field excursion of the Yorkshire Geological Society to Nidderdale, under the leadership of Dr. Wheelton Hind and Dr. Arthur Vaughan, on Friday, April 13th, 1906. One nearly perfect example of this Trilobite from Angram measures 17 mm. long by 10 mm. in breadth. At first sight I took it to be Phillipsia Eichwaldi, but the glabella is more tumid and triangular in form, and the front border projects beyond the margin of the head-shield, whilst it contracts posteriorly to a point at its cervical border, as seen in all typical forms of the genus Griffithides. The cheek-spines are long, and extend to the sixth thoracic segment. The compound eyes are large, and placed laterally, and well behind the projecting and expanded front of the glabella. The posterior point of the glabella ...

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

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.