124 
NAUTILOIDEA. 
the latter leaving a shallow furrow upon the dorsal side. The whole 
surface of the test is covered with fine lines of growth, which are a 
little stronger upon the edges of the peripherj', and form a deep 
sinus upon the latter. 
Some of the specimens vary a little in details of sculpture, the 
smaller ridge in the concave space upon the sides being sometimes 
absent. In fact, according to ^I‘Coy’s description of it, this is a very 
variable species. 
It will be seen that J. de C. Sowerby recognized that C. qiiadratus 
differed from C. suhsulcatus, Phil., sp., as ho made it a variety on 
account of its “shorter aperture” (Trans. Geol. Soc. loc.dt.). His 
excellent figure shows that he had a better specimen than most of 
those which have been collected. 
The present species, though resembling C. subsidcahis in some 
points, differs from it in having a proportionately wider periphery, 
and in the details of its ornaments. 
Horizon. Coal-Measures (English specimens) ; Lower Limestone 
Group ^ (Scotch specimens). 
Localities. Coalbrookdale, Bewdley, Shropshire ; Craigcnglen, two 
miles south of Lennoxtown, Stirlingshire ; Lanark. 
Well represented in the Collection. 
Coelonautilus sulcifer Lcveille, sp. 
1835. Nautilus sulcifer j Leveill^, Mem. Soc. G^ol. do France, vol. ii. 
p. 38, pi. ii. ff. 1, 2. 
1835. Nautilus dorsatus, Leveill(5, ibid. pi. ii. IF. 3, 4. 
1844. Nautilus sulcatus, de Koninck, Hescrip. des Anim. Foss, de la 
Belgique, p. 545, pi. xlviii. ff. 8, 9 (excl. pi. xlvii. ff. 10, a, et 
syuon.). 
1847. Nautilus stdeifer, d’Orhigny, Pal^ont. Universelle, pi. xciii. 
ft-. 6-9. 
1849. Nautilus stdeifer^ d’Orbigny, Prodr. de Pal<5ont. Stratigr. vol. i. 
p. no. 
1854. Nautilus stdeifer, Morris, Cat. British Fossils, 2nd ed. p. 308. 
1860. Nautilus {Discus) trwdcatus, Meek and Worthen, Proc. Acad. 
Nat. Sci. Phil. p. 470. 
1861. Nautilus {Trematodiscus) trisulcatus, Meek and Worthen, ibid, 
p. 148. 
1866. Nautilus {Trematodiscus) trisulcatus, Meek and Worthen, Geol. 
Surv. Illinois, vol. ii. Paleont. p. 162, pi, xiv. ff. 10, a-c. 
^ The rocks of the Carboniferous Limestone Series of Scotland are enume- 
rated in Part I. of the present Catalogue, in the footnote on p. 121. 
^ This must not be confounded wth the Nautilus sidcifenis of Phillips (Geol. 
of Yorkshire, 1836, pt. ii. p. 232), which is probably identical with Coelo- 
nautilus carinifems, J. de C. Sowerby, sp. 
