148 DEVONIAN FAUNA. 



to have, however, more distant septa (fig. 4), and, unless Romer has placed two 

 species under one name, differs also in having annular depressions towards the 

 apical end. Clarke^ further describes this shell, saying that it is the common 

 Orthoceras of the Iberger Kalk, and from his description it is clear that it and its 

 ally, 0. multisejotatum, are distinct from ours. Clarke^ also distinguishes 

 0. laterale from 0. compressum, F. A. Romer, with which Trenkner had 

 identified it. 



0. Ausavense, Steininger,^ is a very small species, differing from the present by 

 the marginal position of its siphuncle, and probably by other features. This 

 species Wahlsmidt* refers, no doubt correctly, to the genus Badrites. 0. affine, 

 Portlock,^ seems more elliptic in section, and more conical. 0. Helmerseni, Pacht,® 

 has a dilate section, an excentric siphuncle, and slightly angulated septa. 

 0. curvescens, Barrande,^ has close, microscopical radiations, and 0. Morrisii, 

 Barrande,® has a constricted aperture and presents less asymmetry. 



14. Oethoceras cf. 0. t^xiale, Barr. PI. XV, fig. 6, 6 a. 



1888. Oethoceeas sp. cf. O. simplicissimum, Foord. Cat. Foss. Ceph. Brit. 



Mus., vol. i, p. 87. 



Description — Shell straight, rapidly tapering, with contour of sides somewhat 

 unequal, slightly expanding above. Septa convex, slightly oblique. Siphuncle 

 central. Section circular. Ratio of tapering about 1 in 6. 



Size. — A portion of the shell measures 60 mm. in length, and 19 mm. in 

 greatest, 16 mm. in least, diameter. 



Locality. — Wolborough. A specimen is in Mr. Vicary's Collection, and another 

 is in the British Museum. 



Remarks. — No signs of the external markings are visible upon either of the 

 specimens, and there is therefore insufl&cient data for defining the species with any 

 certainty. I at first regarded it as an example of 0. laterale, Phillips, to which 

 it evidently is very closely allied ; but afterwards Mr. Foord, Mr. Crick, and 



1 18S4, Clarke, ' Neues Jahrb. fUr Min.,' Beil.-Band 3, p. 334. 



2 Ibid., p. 335. 



3 1853, Steininger, ' Geogn. Beschr. Eifel.,' p. 40, pi. i, fig. 11. 



* 1885, Wahlsmidt, ' tJber Devon. Schicht. Gegend. Wildungen,' p. 921, pi. xxxix, figs. 4o, b. 

 5 1843, Portlock, ' Eept. Greol. Londonderry,' p. 3-7, pi. xxvii, fig. 9. 



" 1858, Baer and Pacht, ' Beitrage Euss. Eeiches,' p. 88, pi. iii, figs. 2, 3 ; and 1863, Semenow 

 and Miiller, ' Mel. Phys. et Chim.,' 'Devon. Sch. Mittel Eussland,' vol. v, p. 673, pi. i, figs. 13 a, b. 



7 1868, Barrande, ' Syst. Sil. Boheme,' vol. ii, pt. 3, p. 183, pi. cclvi, figs. 1—8, Et. E. 



8 Ibid., p. 526, pi. cccl, figs. 9—19 ; atid pi. ccccxlii.figs. 29, 30, fit. D (colony) and E. 



