ORTHOCERATID^. 
GO 
Horizon. Weulock Shales. 
Locality. Gaercod, Monmouthshire. Presented by J. E. Lee, Esq., 
F.S.A., E.G.S. 
Orthoceras Bronni, Barrande. 
1868. Orthoceras Bronni, Barrande, Svst. Sil. de la Boheuie, vol. ii. 
Texte hi. 1874 (ianvier), p. 239, pi. cclviii. IF. 1-9. 
Sj). Char. Shell slightly curved in the young. Section circular. 
Bate of increase from about 1 in 5 to 1 in 8. Length of hod}'- 
chamber about three times the diameter of its base. Septa distant 
about -1- the diameter of the shell. Siphuncle eccentric, placed 
about midway between the centre and the margin. In the young 
the surface is ornamented with horizontal annulations, not very 
prominent, but quite distinct ; these become gradually obsolete as 
the shell increases. The principal ornamentation of the test, how- 
ever, consists ill numerous longitudinal ribs, about 34 in the 
circumference of the shell, and about | of a line distant from each 
other, where the shell has a diameter of 10 lines. The space which 
separates the longitudinal ribs is nearly double the breadth of the 
ribs themselves, and is rather deeply concave. The spaces are 
crossed by fine horizontal stria), and these again by fine, longi- 
tudinal riblets. None of these finer ornaments are preserved in the 
British example, which, being a cast, retains only the longitudinal 
ridges and annulations. 
Remarls. This species is distinguished from 0. viryatam^ Sow., 
by the annulations in the young shell and by the shell-sculpture. 
Horizon. Wenlock Shales. Etago E, bandc e '2 ( = Salopian). 
Localities. British. Dudley, Worcestershire. — Foreiyn. Kosorz, 
Bohemia. 
Fairly well represented in the Collection. 
Orthoceras angulatum, Wahlenberg. 
1731. Species ii. {Sulcati). Major \_and Min(jr~\ ; Gothlandicus, super- 
Jicie bis navies sulcata : Siphonc inter centrum peripheriam . . 
Klein, Descrip, tubuloniin marinoriim, p. 10, tab. v. ff. 8, 9. 
1732. Species v. Ort.hoceratites siphunculo inter centrum Sf peripheriam 
sito yraciliori, &c., Breynius, Dissertatio pliysica de Polythalamiis, 
p. 34, tab. vi. ft*. 3-5. 
1821. Orthoceredites angulatus, Wahlenberg, Nova Acta Beg. Soc. 
Scient. Upsaliensis, vol. viii. p. 90. 
1831. Orthoceratites anyulutus, Hi.singer, Anteckn. i Physik och 
Geognosie, Ilaftet v. p. 112, tab. iv. f. 8. 
1837. Orthoceratites anyulatus, Ilisinger, Lethaea Svecica, p. 28, tab. 10. 
f. 1. 
