ORTHOCERATIDiE. 
119 
was half closed as in Gomplioceras. Xo such appearance is observ- 
able in the specimen in the Xational Collection. 
Horizon. Calcaires Carboniferes blancs = Carboniferous Limestone. 
Locality. Miatchkova, near Moscow. 
Represented in the Collection bj a single example. 
Orthoceras Geinitzi, d'Orbigny. 
1848. Orthoceratites , Geinitz, Die Verstein. des deutscheu 
Zechsteingebirges, p. 0, tab. iii. f. 8. 
1849. Orthoceratites Geinitzii, d’Orbignv, Prodr. de Pal6ont. Strati- 
graphique, p. 1G3. 
1861. Orthoceras Geinitzi, Geinitz, Die Animal. Ueberreste der Dyns, 
p. 43, Taf. xi. f. 8. 
Sp. Char. Shell straight. Section apparently elliptical. Rate 
of tapering about 1 in 9. Septa rather remote, nearly ^ the 
diameter distant from each other. Siphuncle very small, central. 
Surface characters unknown. 
Horizon. Carboniferous Limestone. 
Locality. Asturias, Spain. 
One imperfect example of this species, presented by S. P. Pratt, 
Esq. 
Orthoceras Koninckianum, d'Orbigny. 
1844. Orthoceras anceps, de Koninck, Descrip, des Anim. Fossiles de 
la Belgique, p. 517, pi. xlv. f. 7, a, b (not of Miinster). 
1847. Orthoceratites Konuickianus, d’Orbigny, l*rodr. de Pal6ont. 
Stratigr. prem. vol. p. 1 13. 
Char. Shell straight. Section elliptical. Rapidly tapering 
at the rate of about 1 in 3. Septa distant about. the diameter. 
Siphuncle situated about halfway between the centre and the 
periphery. Surface ornamented with a number of prominent rather 
distant annulations, which form at each extremity of the ellipse a 
small and well-marked sinus. The whole of the surface of the 
shell is covered with very fine, close-set raised lines. 
Bemarks. This species is distinguished from the 0. sulcatum of 
Fleming by its much more rapid rate of tapering, and by the posi- 
tion of the siphuncle. 
Horizon. Coal-Measures (Systeme Houiller). 
Locality. Chockier, Belgium. 
Fairly well represented in the Collection. 
Orthoceras ? pygmaeum, de Koninck. 
1844. Orthoceras pyynueum, de Koninck, Descrip, des Anim. Fossiles de 
la Belgique, p. 507, pi. xlv. f. 5, a, h. 
