OETHOCERATID^. 
Orthoceras Lindstromi, Barrande. 
1870. Orthoceras Lindstromi, Barrande, Syst. Sil. de la Bolieme, vol. ii. 
Texte iii. 1874 (janyier), p. 703, pi. ccccxli. tl. 20, 21. 
Sp. Char. Section apparenlly elliptical. Rate of increase not 
accurately ascertainable, but it is 1 in 8 in the fragment before me- 
Dimensions of body-chamber unknown. Septa apparently strongly 
arched. Siphuncle unknown. Surface ornamented with longi- 
tudinal, irregular, close-set parallel riblets, from 1 to -f a line distant, 
with fine transyerse arched striae between them. 
Bernards. This species is known only b}’ fragments of the body- 
chamber, generally much crushed and distorted. The ornamenta- 
tion is yery similar to that of 0. spectandiim, Barrande ; but the 
latter is a much more slender species, and has a circular section. 
Horizon. Upper Ludlow. 
Locality. Island of Gothland, Sweden. 
The Collection contains two specimens, presented b}' A. H. Uoord. 
Orthoceras spectandum, Barrande. 
1868. Orthoceras spectandum, Barrande, Syst. Sil. de la Boheme, yol. ii. 
Texte iii. 1874 (janvier), p. 223, pi. cclxyi. fi‘. 5-17. 
Sp. Char. Shell straight, or slightly cuiwed. Section circular. 
Rate of increase 1 in 7 to 1 in 6. Length of body-chamber about 
3 times the diameter of its base and about t the total length of the 
shell. Septa distant about 4 the diameter. Siphuncle situated 
about midway between the centre and the margin. Ornaments 
consisting of parallel, longitudinal, acute riblets, irregularly dis- 
posed, sometimes as many as 4 occupying the space of 1 line, some- 
times only 2. The interspaces, Ayhich are coiicaye, are occupied by 
numerous minute transyerse striae. 
Horizon. Etage E, bande e 2 ( = Salopian). 
Locality. Hinter Kopanina, Bohemia. 
Fairly well represented in the Collection. 
Orthoceras dorulites, Barrande. 
1808. Orthoceras doridites, Barrande, Syst. Sil. de la Boheme, yol. ii. 
Texte iii. 1874 (janyier), p. 186, pi. cclxviii. ff. 10-17. 
Sjj. Char. Shell slightly arcuate at its commencement, but after- 
wards straight. Section circular. Rate of increase about 1 in 4. 
Body-chamber not completely known, owing probably to the fragile 
nature of the shell, but from the largest fragments it is judged to 
haye attained a length e;]ual to at least twice the diameter of the 
