0KTH0CERAT1D.12. 
27 
Orthoceras culter, Barrande. 
]868. Orthoceras culter, Barrande, Syst. Sil. de la Bolieme, rol. ii. 
Texte iii. 1874 (janvierl, p. 626, pi. ccxxxix. IF. 9-11, pi. cccxlvii. 
IF. 5-22, pi. ccccxlii. fF. 7, 8. 
Sp. Char. Section oval. Bate of increase variable, from 1 in 20 
to 1 in 27. Septa distant about -J- the diameter; undulating. 
Body-chamber greatly developed ; very variable in length, from 
twice up to six times the diameter of the base. Surface smooth. 
Horizon. Etage E, hande e 2 ( = Salopian). 
Locality. Hinter Kopanina, Bohemia. 
Well represented in the Collection. 
Orthoceras disjunctum, Barrande. 
1868. Orthoceras disjunctum, Barrande, Syst, Sil, de la Boheme, 
vol. ii. Texte iii. 1874 (janvier), p. 6S1, pi. cccxlv. tF. 8-12. 
Sp. Char. Shell always very short. Section circular. Bate of 
tapering about 1 in 7. Septa few in number, generally 2 or 3 
only are found. Body-chamber in length about twice the diameter 
of its base, but sometimes a little less. Siphuncle very slightly 
eccentric. Surface of test smooth, or with faint lines of growth. 
RemarTcs. In all his specimens, numbering about 30, M. Barrande 
could find but very few with more than two or three air-chambers ; 
hence he concludes that, like 0. truncatum, this species cast off its 
septa; moreover, some of the specimens exhibited the terminal cap. 
Horizon. Etage E, hande e 1 ( = Salopian). 
Locality. Butowitz, Bohemia. 
Eairly well represented. 
Orthoceras novellum, Barrande. 
1870, Orthoceras novellum, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874, p. 648, pi. ccxviii. if. 15-18, pi. cccxcvi. fF. 16-20. 
Sp. Char. Section circular. Bale of tapering 1 in 4. Septa 
slightly oblique, about ^ the diameter. The length of the body- 
chamber is equal to about three times the diameter of its base. 
Siphuncle central. Surface smooth. 
Horizon. Etage E, bande e 2 ( = Salopian). 
Locality. Dlauha Hora, Bohemia. 
Fairly well represented. 
Orthoceras Michelini, Barrande. 
1870, Orthoceras Michelini, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874 (janvier), p. 642, pi. ccxxi. ff, 12-19, pi. ccclxxxi. 
ff. 3-16, pi. ccccxlii. fF. 20-23, P pi. ccccxlvii. fF. 12, 13, 
