286 
NAUTILOIDEA. 
Sp. Char. Shell always rapidly expanding, though more so in 
some examples than in others. In the most arcuate forms it 
is found that upon a chord of 50 millim. the highest perpendicular 
is 5 millim. In some specimens, however, the shell is straight 
except in the apical portion, i. e. for about I of the length. The 
transverse section is elliptical, the ratio of the two diameters being 
as 7 : 8. The body-chamber varies considerably in its dimensions in 
different individuals ; its length in some examples is about that of 
the entire shell, in others it is nearly The convex border of the 
aperture has a slight sinus, otherwise it is quite simple. The 
distance between the septa is equal to about yV the diameter of the 
shell. The siphuncle is close to the convex border, without touching 
the test ; its elements are elongated and cylindrical. The surface of 
the test is ornamented with strong transverse striae, having a 
direct imbrication, upon these still finer lines are seen in the upper 
part of the shell. Longitudinal Hues are met with upon the upper 
part of the body-chamber ; they are variable in number in different 
individuals, and are somewhat widely spaced. 
Remarlcs. The present species is distinguished from others of 
similar character by the longitudinal lines upon its test. 
Horizon. Etage E ( = Salopian). 
Localities. Karlsteiu, Kosorz, Bohemia. 
Fairly weU represented in the Collection. 
Cyrtoceras (Meloceras) obesum, Barrande, sp. 
1848. Cyrtoceras obesum, Barrande, Haidinger, Bericbte fiber die 
Mittheil. von Freund, d. Naturwiss. in Wien, Band iv. p. 209. 
1852. Cyrtoceras ohesum^ Giebel, Fauna der Yorwelt, Band iii. Abth. i. 
p. 209. 
1867. Cyrtoceras ohesum, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 557, pi. cxiv. ff. 22-26. 
1877. Cyrtoceras ohesum, Barrande, ibid. Suppl. et Ser. tardive, p. 163, 
pi. dviii. ff. 6-8, pi. dxxi. ff. 10-13. 
/Sp. Char. Shell pretty strongly curved; upon a chord of 50 
millim., subtending the con^cave side, the highest perpendicular is 
8 millim. The transverse section is nearly circular, the ratio of the 
two diameters being as 11 : 10. The rate of increase in the septate 
part of the shell is about 1 in 2. The body-chamber occupies 
about of the total length of the shell ; there are crenulations at 
its base in some examples b The plane of the aperture is slightly 
inclined towards the concave side ; there is a slight constriction 
^ See Barrande, loc. cit. pi. dviii. f. 6. 
