302 
NAFIILOTDEA. 
consist of transverse striae of growth, which are sometimes lamellose, 
and these are often accompanied by very fine longitudinal striae 
which cut through the former. The transverse striae form a 
shallow sinus on the convex border of the shell. 
Remarlcs. The remarkable changes in tbe position of the siphuncle 
in the present species might have been held sufficient for the 
establishment of a great many species, were it not for the fact 
that examples are met with connecting the extreme cases above 
mentioned \ 
M. particeps^ Barr. sp. (pi. clxxxvi.), resembles the present species 
in its general form, but is distinguished by the great relative de- 
velopment of the septate part, and by the longitudinal ridges upon 
its internal cast. 
Horizon. Etage E, baude e 2 ( = Salopian). 
Locality. Karlstein, Bohemia. 
Well represented in the Collection. 
d. Position of siphuncle unknown or clouhtful. 
Cyrtoceras (Meloceras) Barrandei, Salter, sp. 
1851. Orthoceras Bari'andci, Salter, Quart. Journ. Geol. Soc. vol. vii. 
p. 177, pi. ix. f. 19. 
? 1867. Cyrtoceras cemulus, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 540, pi. ccxl. ff. 7-10; ibid. 1877, Siippl. et Sdr. tardive, 
p. 17, pi. cccclxxxi. fi*. 25-33, p. 114, pi. dvii. ff. 1-5. 
1873. Phragmoceras (^Gomphocei'as) liratum, Salter, Cat. Cainbr. & 
Sil. Foss. p. 174. 
? 1882. Orthoceras Barrandei, Blake, British Foss. Ceph. pt. i. p. 79, 
pi. xviii. ff. 10-12, pi. xix. ff. 4, 4 a. 
Sp. Char. “ Short, tapering at an angle of 40° ; acute at the ex- 
tremity; the mouth broad and very oblique, surface covered by 
regular close ridges of growth, which are not waved, but pass 
obliquely across parallel to the mouth ; septa in the same direction, 
occupying half the length of the shell, and about ^ their diameter 
apart.” (Salter.) 
Remarks. The type specimen, which is contained in the IMuseum 
Collection, is so buried in the matrix that only about half of it can 
be seen. Another specimen, figured by Blake (loc. cit. pi. xviii. 
f. 11), is also in an unsatisfactory condition of preservation. Its 
septa are wider apart than those of the type, and it may perhaps 
belong to a different species. I am not able to identify it with any 
of Barrande’s. 
1 See Barrande, Syst. Sil. de la Boheme, vol. ii. Texte iv. 1877, p. 566, — 
“ Anomalies dans la position du Siphon des Nautilides.” 
