506 J. T. Stohhs—On Anthracomya Phillipsi. 



The followiug dimensions in millimetres are taken from specimens 

 collected by myself in the ossiferous breccia of Monte San Giovanni, 

 near Iglesias (South-west Sardinia). 



Cranium Imperf. cranium Mandibular rami 

 (B.M. M. 8156). (B.M.M.3488). (B.M. M. 3488). 



In five upper jaws (M. 34:88c, d, e, f, and g) the length of the 

 upper molar series is respectively 6'9, 6'8, 65, 65, 7*1. In 

 nineteen upper jaws remaining in my hands, the length of the upper 

 molar series varies from 6*3 to 7*3. These two extremes are 

 represented by only one specimen each. The remaining seventeen 

 have the following dimensions: — Three, 6*4; three, 6'o; three, 66; 

 five, 6-7; one, 6*8; two, 7. 



VI. — The occurrence of Anthbacomya Phillipsi in the Durham 



Coalfield. 



By John T. Stobes, F.G.S. 



'^PHIS important Coal-measure zonal Lamellibranch has already 

 X been recorded from the Yorkshire and Nottingham Coalfield 

 (Cadeby and Gedling Colliery respectively), the Lancashire Coal- 

 field (Ardwick, Manchester), the North Staffordshire Coalfield 

 generally, the Forest of Dean and Bristol Coalfields, the South 

 Wales Coalfield ; and in all these widely separated districts it is- 

 found at the top of that portion of the Coal-measures characterised 

 by the presence of the most valuable seams of coal. 



In North Staffordshire Anthracomya Phillipsi, atone part of its zone,- 

 is associated with Carbonicola vinti, and this horizon has been widely 

 traced.' Now, Carbonicola vinti was first recorded by J. W. Kirkby 

 from the Coal-measures near Hylton in the county of Durham, 

 under the name of Ancyhis vinti,'~ and being familiar with the 

 occurrence of these two forms in North Staffordshire the writer felt 

 that the Hylton section should be specially searched for Anthracomya 

 Phillipsi. Accordingly, on 25th August last an opportunity was 

 afforded him of visiting Kirkby's section, which he experienced no 

 difficulty in recognising from Kirkby's description. The locality 

 now threatens to attract a denser population, and it may be wise to 

 give the position of the exposure with greater precision. It occurs 

 on the left bank of the Kiver Wear (lat. 54° 55' 5" N. ; long. 

 1° 26' 50" W.), and is marked on the Geological Survey maps by 

 a fault. It is true that the Coal-measures abut against the Permian 

 yellow sands as sketched by Kirkby in the paper referred to, but 



' "Wheelton Hind: Quart. Journ. Geol. Soc, vol. Iv, pp. 367-8. 



' James W. Kirkby : Trans. Tyneside Nat. Field Club, vol. \i, pp. 220-225. 



