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Genus — PLATY CERAS, Conrad. 
Platyceras angustum, J . Phillips . 
PI. XXIIT, Pig. 7. 
Fileopsis angustus, J. Pbillips, 183G, Geol. Yorkshire, II, p. 224, pi. 14, fig. 20. 
Acroculia angusta, J. Morris, 1843, Cat. Brit. Boss., p. 137. 
,, angustcitci, P. McCoy, 1844, Synop. Carb. Poss. Irelaud, p. 44. 
Capidus neritoides, H. G-. Bronn, 1848, Index Pal., p. 214 (non Phillips). 
,5 angustus, J, Morris, 1854, Cat. Brit. Poss., 2nd edit., p. 239. 
The sliell of this species is not symmetrical, its right side being much 
more developed than the left, which is depressed laterally to such an extent 
that its aperture is obliquely oval ; the rest agrees perfectly with the figure 
given by Phillips. Its apical extremity is very pointed, and is whorled 
obliquely, forming nearly two spiral turns in contact. The surface is nearly 
smooth, showing only distinct lines of growth. 
Dimensions . — The height is thirteen millimetres, and the largest 
diameter of the ajierture sixteen millimetres. 
Delations and Differences . — This sj)ecies is closely related to P. vetus- 
tum, Sowerby, P. procunihens, De Pi-yckholt, and P. trilohus, Phillips, from 
which it differs by the greater asymmetry of its sides, by its more oblique 
and oval aperture, by the contiguity and stronger curve of the spire. 
Dorizon and Localities . — Phillips found it in the Garboniferous 
Limestone at Bolland, in Yorkshire. The Australian specimen came from 
Burragood. 
Platyceras trilobatum, J. Dhillips. 
Dileopsis ? trilohus, 
Capulus vetustus, 
Dlatyceras trilohalum, 
Acroculia triloba, 
J. Phillips, 1836, Grcol. Yorkshire, II, p. 224, pi. 14, fig. 12, 13. 
L. Gr. de Koniuck, 1842, Descr. Anim. Poss., p. 332 (non 
Sow.). 
J. Morris, 1843, Cat. Brit. Poss., p. 157. 
P. McCoy, 1844, Synop. Carb. Poss. Ireland, p. 45. 
