OETHOCEKATIDiE. 
55 
that district, and there can be no further doubt about its true 
horizon. Moreover, Sowerby himself insisted upon the identity of 
his type with the species collected elsewhere by Sir Eoderick Mur- 
chison, and figured by him in the ‘ Silurian System ’ \ 
Horizon. Wenlock Limestone (Salopian). 
Localities. Goalbrookdale, Shropshire; Walsall, Staffordshire; 
Gaercoed, near ITsk, Monmouthshire. A specimen from the latter 
locality was presented by J. E. Lee, Esq., E.G.S. 
A very fine series of examples represents this species and its 
varieties. 
Var. crassum, var. nov. 
1827. Orthoceratites undulatus, Hisinger, Vetensk. Akad. Handliugar, 
Sednare Halften, p. 323, tab. vii. f. 8. 
1831. Orthoceratites undulatus, Hisinger, Auteckn. i Physik och Geog- 
nosie, Femte Haftet, p. 112, tab. iv. f. 6. 
1837. Orthoceratites undulatus, Hisinger, Lethaea Svecica, p. 28, tab. x. 
f. 2. (Not of Sowerby.) 
1839. Orthoceras annulatum, Sowerby, in Murchison’s Sil. Syst. p. 632, 
pi. ix. f. 5. 
1852. Orthoceras (Cucloceras) annulatum, M‘Coy, British Pal. Foss, 
fasc. ii. p. 319. 
1854. Orthoceras annulatum, Salter, in Murch. ‘ Siluria,’ pi. xxvi. f. 1 . 
1857. Orthoceras anmdatmn, Boll, Archiv des Yer. der Freimde der 
Naturgesch. in Mecklenburg, xi. Jahrg. p. 25, Taf. vii. f. 23. 
? 1858. Orthoceras anmdatum, Schmidt, Archiv fiir die Naturkimde 
Liv-, Ehst- und Kurlands, Zweiter Band, p. 197. 
1867. Orthoceras annulatum, Dixon, Trans. Woolhope Naturalists’ 
Field-Club, Fossil Sketches, No. 1. f. 5. 
1868. Orthoceras annulatum, Barrande, Syst. Sil. de la Boheme, vol. ii. 
Texte iii. 1874 (janvier), p. 308, pi. ccxxv. f. 23, pi. ccxc., pi. ccxci. 
ff. 1-4, ?5, 6, 15-17. 
? 1869. Orthoceras annulatum, Heidenhain, Ueber Graptholithen fiih- 
rende Diluvial-Geschiebe der norddeutsclien Ebene, p. 20. 
1870. Orthoceras annulatum, Barrande, ibid. pi. ccccxli. ff. 2-5 {not f. 1). 
1882. Orthoceras annulatum, Blake, British Foss. Ceph. pt. i. p. 89, 
pi. iv. ff . 1,2, 5, 0-8. 
\_Not 1831. Orthoceratites annulatus, Hisinger, Auteckn. Femte Haftet, 
p. 112, tab. iv. f. 5. — 18.36. Orthoceras annulatum, Phillips, Geol. 
Yorkshire, vol. ii. p. 239, pi. xxi. ff. 9, 10. — 1837. Orthoceratites 
annulatus, Hisinger, Lethaea Svecica, p. 29, tab. ix. f. 8.] 
The great majority of examples figured and described under the 
name Orthoceras annulatum differ from Sowerby’s type in the cha- 
racter of their ornamentation to such an extent as, I think, justifies 
^ Sil. Syst. 1839, footnote, p. 632. 
