CYETOCEEATID^. 
283 
Remarhs. A comparison has already been instituted between 
M. jprohlematicwm, Barr., and the present species. 
Horizon. Etage E (= Salopian). 
Locality. Dlanha Hora, Bohemia. 
Well represented in the Collection. 
Cyrtoceras (Meloceras) tardum, Barrande, sp. 
1867. CyHoceras tardum, Barrande, Syst. Sil. de la Boheme, toI. ii. 
pt. i. p. 533, pi. cxvi. ff. 10-22, pi. cxlvii. S. 39-48. 
Sp. Char. This species is characterized by its very strong cur- 
vature, uniformly developed throughout the whole length of the 
shell, and making almost a complete whorl. The transverse section 
is elhptical, the ratio of the two diameters being as 18 : 17. The 
increase is in the ratio of 1 to 2 in a length of 50 millim. measured 
in the septate part of the shell. The body-chamber is nearly as 
wide at the base as it is at the aperture ; its length is a little less 
than that of the ventro-dorsal diameter at the aperture, or J the 
length of the shell. The distance between the septa is in the 
largest examples of the ventro-dorsal diameter. The siphuncle 
is placed close to the convex border, but without touching the test. 
The latter is ornamented with regular, transverse, very close-set 
striae, which make a very distinct sinus in the median line of the 
convex border ; a few faint longitudinal lines are sometimes seen 
crossing these. 
Remarlc's. M. yihhum, Barr. (pi. cxxix.), is a very closely allied 
species, but its septa are more approximate in the upper part of the 
shell, and its ornaments, though of the same character as those of 
M. tardum, are coarser. 
Horizon. Etage E (= Salopian). 
Locality. Karlstein, Bohemia. 
Represented in the Collection by two imperfect specimens. 
Cyrtoceras (Meloceras) velox, Barrande, sp. 
1867. Cyrtoceras velox, Barrande, Syst. Sil. de la Boheme, vol. ii. pt. i. 
p. 538, pi. cliv. ff. 14-24, ? pi. clvii. IF. 20-24, pi. ccxl. bis. IF. 10-18. 
Sp. Char. Curvature well marked and nearly uniform throughout 
the whole length of the shell. Upon a chord of 55 millim., sub- 
tending the concave side of the largest specimen measured, the 
highest perpendicular is 10 millim. The transverse section is 
nearly circular at the apex, but becomes elliptical in the adult part 
