CTRTOCEEATID^. 
267 
Horizon. Stringocephalen-Kalk, Middle Devonian (Gerolstein) ; 
Goniatiten-Kalk (Adorf) ; Iberger-Kalk (Winterberg) ; Upper 
Devonian. 
Localities. Gerolstein, Eifel ; Adorf, Waldeck ; Winterberg, North- 
western. Hartz. 
Fairly well represented in the Collection. The specimen from 
Adorf was presented by J. E. Lee, Esq., E.S.A., F.G.S. 
Cyrtoceras lineatum, Goldfuss. 
1832. Cyrtocera lineata, Goldfuss, in von Decheu’s Handb. der Geognosie 
von H. T. De la Beche, p. 536. 
1833. Orthoceratites calycularis, Steininger, Mem. Soc. G^ol. de France, 
vol. i. p. 369, pi. xxiii. f. 2. 
1833. Orthoceratites ventricosus, Steininger, Mem. Soc. Gt^ol. de France, 
vol. i. p. 368, pi. xxii. f. 5. 
1842. Cyrthoceratites lineatus, d’Archiac Sz de Verneuil, Trans. Geol. 
Soc. 2nd ser. vol. vi. pt. ii. p. 351, tab. xxx. ff. 2, 2 a. 
1843. Cyrtoceras ventricosum, Boemer, Die Verstein. des Harzgebirges, 
p. 35, tab. X. f. 1. 
1849. Cyrtoceratites depressus, Quenstedt, Die Petrefactenkunde 
Deutschl. Band i. Abth. i. p. 47, tab. i. ff. 17, «, h. 
1849. Cyrtoceras lineatum, d’Orbigny, Prodr. de Paleont. Stratigr. 
vol. i. p. 53. 
? 1850. Cyrtoceras multiseptatum, Boemer, Beitrage z. Geol. Kenntn. 
des Nordwestl. Harzgebirges, p. 38, tab. vi. f 2. 
1852. Cyrtoceras Kessiyi, Giebel, Fauna der Vorwelt, Baud iii. Abth. i. 
p. 201. 
Sj). Char. Shell large, rapidly expanding, slightly curved, so 
that upon a chord of 38 lines subtending the concave side the 
highest perpendicular is only two lines. Section slightly elliptical, 
the ratio of the dorso-ventral to the transverse diameter (in an un- 
compressed example) being as 45 : 48. The septa are very slightly 
concave, and increase in their distance apart from 2^ lines, where 
the shell has a diameter of 20 lines, to 5 lines where the diameter 
has increased to 48 lines. The siphuncle is of medium size and 
increases with the growth of the shell ; it is seven lines in diameter 
where that of the shell is 48 lines ; the interior is filled with 
radiating deposits. The shell is “ marked externally with irregular, 
simple, sinuous lines of growth, which turn backward and pass above 
the siphon. The internal lamina of this shell presents longitudinal 
folds on each side of the back, which are often obsolete, but still 
distinct enough.” {d’Arcli. ^ de Vern.) Nothing is at present known 
of the body-chamber of this species. 
