4 Jackson, On a New Carboniferous Nautiloid. 



Scotland, but in that form the whorls are more subquadrate in transverse 

 section and usually bear distinct longitudinal lateral grooves (the edge 

 of the umbilicus being separated by a shallow groove from the inflated 

 part of the whorl), whilst the umbilical zone slopes towards the centre 

 of the umbilicus, instead of being perpendicular to the mesal plane of 

 the shell as in the present species. The same characters distinguish 

 the present species from the form described and figured by J. de 

 C. Sowerby* as Nautilus subsukatus var., from the Coal-measures of 

 Coalbrookdiile, Shropshire. 



Both C. subsukatus and C. quadratus occur in lists of Pendleside 

 fossils from High Green Wood, etc. ;t also in lists of fossils from tlie 

 Lower Coal-Mcasures.J Specimens in the Manchester Museum 

 (Gibson Collection) hitherto labelled as C. subsukatus have turned out 

 to belong to, at least two species, viz., Pkuronautilus pulcher Crick, 

 and another probably new species. In like manner the Marsden 

 specimen dealt with in this paper, was recorded and labelled as 

 C. subsukatus by Barnes and Holroyd. It seems, therefore, desirable 

 to expunge C. subsukatus Phil., and probably also C. quadratus Flem., 

 from the lists of Pendleside and Coal-measure fossils until authentic 

 specimens are obtained. 



Horizons and Localities. — Lower Coal-measures (Roof of the Bullion 

 coal). Townhouse, near Colne, Lanes. (E coll. Wild, W669). 

 Pendleside Series, Pule Hill, Marsden, Yorks. (Ecoll. Holroyd, L2827) ; 

 Dr. Wheelton Hind also possesses three specimens of this new species 

 from the Lower Coal-Measures of Shibden, and one specimen from the 

 Millstone Grit Series of Eccup. 



* Trans. Geol. Soc. London, vol. V., part 3, 1840, p. 492, and Explanation 

 of Plate xl., fig. 7. 



t Davies and Lees, "West York.shire," 187S. p. 99; Barnes and Holroyd, 

 Trans. Manch. Geol. Soc, XXIV., 1896, p. 90; Hind, Quart. Journ. Geol. Soc, 

 vol. 57. 1901, p. 372, etc. 



X Bolton, Trans. Manch. Geol. Soc, XXVIIL, 190^, p. 394 and p. 647 ; and 

 Report of the Mollusca Committee to the Council of the Manchester Geologual 

 Society, October, 1910. 



