ORTHOCERiL'flD.E. 
2i 
1878. Orthoceras cnf. migrans^ Kayser, Die Fauna der altesten Devon- 
Ablagerungen des Harzes, in the Ahhandl. zair geol. Specialkarte 
Ton Preiissen, Band ii. Pleft i. p. 71, Taf x. ff. 6, 6a. 
1882. Orthoceras distans, Blake, British Foss. Ceph. pt. i. p. 158, 
pi. XV. ff. 1, 2. 
Sjg. Char. Section circular or subelliptical. Kate of tapering 
1 in 8. Septa direct ,• their distance exceeding | the diameter of 
the shell. The length of the bodj'-chamber in a small flattened 
example measured times its basal diameter. Siphuncle eccentric, 
somewhat inflated between the septa. Surface smooth, or with 
obscure striae of growth. 
Eemarhs. Blake’s flgure of this species has a higher rate of 
tapering than any of Barrande’s, and the septa are more strongly 
arched in the figures of the latter author. 
Kayser’s fossil is thus described : — A large, thick form, very 
slowly increasing in breadth, with circular cross section. Septa 
strongly convex, chambers about twice as broad as high, siphuncle 
very eccentric. Test unknown.” 
Horizon. Calcaires ampeliteux ( = Third Fauna of Barrande). — 
Etage E of Barrande ( = Salopian ?). 
Localities. FeugueroUes (Calvados), France ; Germany ; (? Bo- 
hemia). 
Fairly well represented in the Collection. 
Orthoceras politum, M‘Coy. 
{Ante, p. 7.) 
Eemarhs. This species is recorded by Barrande in his ‘ Distribu- 
tion des Cephalopodes,’ 1870, p. 50, under the name of Orthoceras 
lancea ? 
Horizon. Calcaires ampeliteux (=Third Fauna of Barrande). 
Locality. FeugueroUes (Calvados), France. 
Orthoceras Arion, Barrande. 
1866. Orthoceras Avion, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874 (Janvier), p, 619, pL ccxxi. f. 24, pi. cccxlvii, 
fl*. 1-4, pi, ccccviii. fl*. 9-14, 
1870, Orthoceras Avion ?, Barrande, Distrib. des Ceph. dans les 
Contrees Siluriennes, p. 60 (Extrait du Syst. Sil. de la Boheme, 
vol. ii. 4me ser.). 
1876. Orthoceras Avion, Tromelin and Lebesconte, Assoc. Fran^. pour 
I’avancement des Sciences, 4m e Sess. (Nantes), Tableau B. 
1878. Orthoceras sp., Bayle, Explication de la Carte Geol. de la 
France, tom. iv., Atlas, premiere partie, pi. xxxiv. ff. 7, 8. 
Sp. Char. Section circular. Kate of increase 1 in 6. Septa 
