CTETOCEKATIDiE. 
315 
shallow sinus on its sides. The siphuncle is situated close to the 
convex border. The test is ornamented with pretty distinct, 
rounded annulations, which form a narrow sinus on the convex 
border ; their surface is covered with fine striae of growth. 
RemarTcs. The species having the closest affinity with the present 
one is C. sociale^ Barr., hut it differs notably from the former in its 
ornaments, rate of tapering, and other minor characters. 
Horizon. Etage E, bande e 2 ( = Salopian). 
Localities. Eworetz, Dlauha Hora, Bohemia. 
Fairly well represented in the Collection. 
Cyrtoceras (Ooceras ?) sequale, Barrande, sp. 
1848. Cyrtoceras (equate, Barrande, Haidinger, Bericht fiber die Mit- 
theil. von Freund, der Naturwiss. in Wien, Band iv. p. 209. 
1852. Cyrtoceras (equate, Giebel, Faima der Vorwelt, Band iii. Abth. i. 
p. 209. 
1807. Cyrtoceras (equate, Syst. Sil. dela Bolieme, vol. ii. pt. i. 
p. 479, pi. cviii. ff*. 13-18, pi. ccii. ff‘. 14, 15. 
Sp. Char. Shell strongly curved. Upon a chord of 105 millim., 
subtending the concave side, the highest perpendicular is 27 millim. 
The transverse section is oval, the narrower end corresponding with 
the convex side of the shell. The ventro-dorsal is to the transverse 
axis about as 4:3. The increase in diameter is rapid in the 
inferior third of the shell, where the ventro-dorsal diameter in- 
creases in the ratio of 1 to 3 in a length of 50 millim. The body- 
chamber is very short. In adult shells it is about equal to the 
ventro-dorsal diameter of the aperture, and occupies about -J- of the 
total length of the shell. The distance between the septa increases 
slowly, reaching a maximum of about ^ of the ventro-dorsal dia- 
meter. The siphuncle is situated close to the convex border, but 
without touching the test. The surface of the test is covered with 
somewhat irregular striae of growth, which in the upper part of the 
shell assume the aspect of imbricating lamellae. 
RemarJcs. The species most nearly allied to the present one is Ooc. 
sociale, Barr., sp., which is, however, clearly distinguished by the 
ornaments of the test, consisting of well-marked imbricating 
plications. 
Horizon. Etage E ( = Salopian). 
Locality. Lochkow, Bohemia. 
Represented in the Collection by a single example. 
