ORTHOCEEAIID^. 
37 
Orthoceras pelagium, Barrande. 
1870. Orthoceras pelagium, Ban-ande, Syst. Sil. de la Bobeme, vol, ii. 
Texte iii. 1874 (janvier), p. 444, pi. ccclxxi., pi. ccclxxv. ff. 13-15; 
id. Siippl. Ser. tardive, avril 1877, p. 217, pi. dxxi. ff. 1-3. 
1876. Orthoceras pdayium, Tromeliu & Lebesconte, Assoc. Fran9. 
pour ravancement des Sciences, 4me Sess. (Nantes), Tabl. B. 
Sp. Char. Section elliptical, the ratio of the two diameters being 
as 12 : 11. Bate of increase abont 1 in 11. Septa distant a little more 
than i the diameter. Length of body-chamber a little less than 3 
times the greater diameter of its base. Siphuncle very slightly ec- 
centric. Surface-ornaments consisting of striae having an obliquity of 
about 15^; they have a direct imbrication, not very distinctly marked. 
Horizon. Etage E, bande e 2 ( = Salopian). 
Localities. Blauha Hora, Karlstein, Bohemia. 
Several good examples in the Collection. 
Orthoceras duplicans ?, Barrande. 
1868. Orthoceras duplicans, Barrande, Syst. Sil. de la Bobeme, vol. ii. 
Texte iii. 1874 (janvier), p. 431, pi. cccv. ffi 22-27. 
1878. Cnf. Orthoceras commutatum, Giebel, Kayser, in Geol. Special- 
karte von Preussen ; Die Fauna der iiltesten Devon. 
Sp. Char. Section circular. Bate of increase 1 in 7. Septa 
distant about 4 the diameter. Length of body-chamber about 3 times 
the diameter of its base. Siphuncle central. Surface-ornaments con- 
sisting of fine horizontal imbricating strim, which vary in their 
distance and strength in the same individual. 
Hemarh's. Some imperfect specimens, with fragments of the test 
adhering to some of them, are assigned, with a degree of hesitation, 
to the present species. 
Uoiizon. Etage E ( = Salopian). 
Locality. Bohemia. 
Orthoceras Murchisoni, Barrande. 
1868. OHhoceras Murchisoni, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874 (janvier), p. 528, pi. ccliv. ff. 4-6, pi. ccciii. ff, 
11, 12, pi. cccx. ff. 1-3, pi. cccxvi. ff. 1-3, pi. cccxx. ff. 5-10, 
pi. cccxxi. ff. 1-12, pi. cccxxxi. ff. 1-3, pi. ccccviii. ff. 1-8, pi. 
ccccxlv. ff. 12, 13, pi. cccclv. ff. 1-3. 
Sp. Char. Section elliptical. Bate of tapering very variable, 
from 1 in 15 to 1 in 5. Septa distant about \ the diameter, with 
an obliquity of about 35°. Body-chamber with a length of nearly 
3 times the diameter of its base. Siphuncle nearly central at first, 
hut assuming gradually an eccentric position, until it is situated 
midway between the axis and the circumference. Surface with 
oblique lamellose striae. 
