250 
NAUTILOIDEA. 
the ventro-dorsal is to the transverse axis as 4 : 3. The neck is of 
a cylindrical form, with circular section, of which the diameter is 
about |- of the total width of the fossil. The aperture is circular 
and a little oblique, its inclination corresponding to the convex or 
ventral border of the shell. The central or constricted part of the 
body-chamber represents at least half of the total length of the 
latter. The septal chambers occupy a little more than half the 
transverse diameter of the shell, there are generally four of them, 
but sometimes five ; there is a slight sinuosity in their sutures on 
the dorsal side. The last two septa are always closer together than 
the rest. The lower part of the body-chamber is much dilated, and 
occupies a little less than ^ of the total length of the fossil. AYhen 
the test is preserved at the truncated extremity it is found to be 
devoid of ornament. This part is separated from the rest by a line 
which indicates the loss by truncation of the earlier septate portion 
of the shell, because we find upon the truncated surface, midway 
between its centre and the convex border, a little siphunclar neck, 
slightly projecting from the surface and showing a narrow opening. 
When the posterior extremity of the body-chamber is laid bare by 
the loss of the lowest septal chamber, the siphuncular opening is 
seen near the margin. The test in this species is ornamented with 
extremely fine regular longitudinal lines, scarcely visible to the naked 
eye ; these are crossed by still finer transverse lines. The longitu- 
dinal lines are generally the stronger of the two, but sometimes the 
transverse lines take their place in this respect. 
Remarhs. This species is well distinguished from others by its 
ornamentation. 
Horizon. Etage E, band e 2 ( = Salopian). 
Locality. Karlstein, Bohemia. 
Eairly well represented in the Collection. 
Ascoceras Verneuili, Barrande. 
1867. Ascoceras Verneuili, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 359, pi. xcv. ft'. 42-57. 
/Sy). Char. The general form of this species is cylindrical, obliquely 
truncated posteiiorly, with an elliptical section. The septal side is 
nearly straight, the other side a little convex. The neck or anterior 
prolongation of the body-chamber is not constricted ; it is extremely 
short, so that in an example that measures 23 lines in length it 
scarcely exceeds 1 line (fig. 43, g). The constricted part of the 
body-chamber occupies more than of the total length of the fossil, 
and receives the septal chambers to the number of six or seven, in 
