ASCOCEEATID^. 
249 
of the body-chamber, now much compressed, so that the long diameter 
in the plane of symmetry is in the ratio of 5 to 2 to the short one. 
The radius of curvature is about inches at first. The whole body- 
chamber has a length, as preserved, equal to twice its greatest 
breadth. The aperture appears simple, and has a diameter the 
greatest breadth. The ornaments are acute, separate riblets .... 
varying in distance from 6 per line at the base to 14 per line near 
the aperture. The ordinary septa have a convexity of J the long 
diameter. The sutures are straight, but oblique to the general 
direction of the shell, slanting back to the convex side. The 
siphuncle is moderately large, and is situated ^ the diameter from 
the convex side. The sigmoid septa are not more than two in 
number, and their curvature is not great, as they make an acute 
angle with the part of the shell above them on the concave side. 
The second succeeds the first in a nearly horizontal direction. They 
occupy a length of the whole chamber. Length 2J inches ; 
greatest breadth 1 inch.” 
Remarhs. Blake points out that Salter’s statement as to A. Bar- 
ranclei being a larger and thicker species than A, Boliemicum, Barr., 
with more oblique lines of growth and more strongly sigmoidal septa, 
is erroneous. “ No specimen of the present species,” observes Blake, 
has been found of anything like the dimensions of the Bohemian 
form, and the obliquity of the lines of growth is well matched in the 
latter.” Purthermore, the septa in the present species are much less 
curved than they are in A. Boliemicum, 
Horizon. Upper Ludlow. 
Locality. Ludlow, Herefordshire. 
Eepresented by a single example presented by J. E. Lee, Esq., 
E.S.A., E.G.S. 
Ascoceras Murchisoni, Barrande. 
1867. Ascoceras Murchisoni, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 357, pi. xcv. ff. 1-35. 
1877. Ascoceras Murchisoni, Barrande, ibid. Suppl. et Serie tardive, 
p. 98, pi. ccccxci. if. 3-7. 
Sjy. Char. Shell varying in its form with age, the constricted 
part near the aperture occupying about y of the total length of the 
shell in some individuals, whilst in others this proportion increases 
to I and even to Furthermore, this constricted part is more or 
less inclined in some specimens towards the straighter or dorsal side 
of the shell, and in others it conforms to the longitudinal axis. The 
horizontal section taken in the middle of the shell is oval, of which 
