ORTHOCEBAIID^. 
59 
Orthoceras Bohemicum^ Barrande. 
1855. Orthoceras Bohemieum, Barrande, Bull. Soc. Geol. France, 2^ s6r. 
tom. xii. p. 450. 
1857. Orthoceras Bohemieum, Meneghini, Paleont. de I’De de Sar- 
daigne, p. 117, pi. C. ff. 6, 6 a, Gu'. 
1866. Orthoceras Bohemieum, Barrande, Syst. Sil. de la Bolieme, toI. ii. 
Texte iii. 1874 (janvier), p. 315, pi. eexiv. ff. 11-13, pi. eexv. 
ff. 8-11, pi. cclxxxviii., pi. cclxxxix. If. 7, 8, pi. ceex. f£. 16-19. 
Sp. Char. Section circular in the majority of specimens, but in 
some a little elliptical. Bate of increase about 1 in 7, but very 
variable. Body-chamber attains a length equalling 5 or 6 times 
the diameter of its base. The septa are distant about f the dia- 
meter, with a convexity of about | ; they are regular and horizontal. 
Siphuncle central, or but very slightly eccentric. Surface with 
broadly rounded oblique annulations, separated by spaces as wide as 
they ; these annulations completely disappear upon the dorsal side 
of the shell and upon its basal extremity {cf. 0. dimidiatum, loc. cit. 
p. 52). The surface of the test is covered with line striae running 
parallel to the annulations. Sometimes feebly marked longitudinal 
striae are to be seen. 
Remarl's. The siphuncle in the Bohemian form is somewhat 
smaller, relative to the shell-diameter, than it is in the Sardinian 
one, the ratio of the former being as 1 : 10, that of the latter as 
1 : 7. 
This species has a wide geographical distribution. M. de Ter- 
neuil, in a communication to the Geological Society of France (Feb. 
1850), cites it from the basal deposits of the Silurian at St. Beat 
(Hautes-Pyrenees), giving a description of its salient characters. 
It has also been found in the Province of Gerona (Northern Spain 
and in Sardinia. 
Horizon. Etage E, band e2 ( = Salopian). 
Localities. Hinter-Kopanina, Karlstein, Dworetz, Bohemia. 
Bepresented by very fine specimens. 
Orthoceras subannulare} Munster. 
1840. Orthoceratites suhannularis, Munster, Beitr. z. Petref. Heft iii. 
p. 99, Taf xix. f. 3. 
1852. Orthocei'as {Cycloceras)? subanmdatum, M‘Coy, British Pal. 
Foss. fasc. ii. p. 320. 
1866. Orthocei'os suhannulare, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874 (janvier), p. 343, pi. ccx. ff. 8-10, pi. ccxii. ff. 14- 
18, pi. ccliii.ff. 11-14, pi. cclxxxiii. (except ff. 11, 12 ?), pi. cccxxiii. 
'■ Lucas MaUada, “ Fosiles de Espana,” Bol. Com. del Mapa Geol. de Espafia, 
1875, tom. ii. p. 25. 
