ORTHOCERAS. 149 



myself, on comparing it with examples in the British Museum, came to the 

 conclusion that it could not belong to that species on account of the decidedly 

 greater proximity of its septa ; and this difference is certainly borne out by other 

 specimens of the latter shell which I have elsewhere examined. It appears to 

 come midway between the two species described by Phillips as 0. laterale 

 and 0. imbricatmn. 



As far as the specimen goes, I can see no difference between it and 0. txniale, 

 Barrande.^ In the latter shell the external ornament consists in fine regular 

 upward imbrications, which are rather closer than the septa, but become still closer 

 at the upper end, a style of ornament which I do not know among Devonshire 

 specimens. 



0. timidmn, Barr.,^ is a smaller and more elongate form. 



The specimen in the British Museum is labelled 0. cf. simplicissimum, Sand- 

 berger, which is a shell nearly resembling the last species, under the heading of 

 which I have noted it. In some points, as, for instance, the circular section and 

 the size of the siphuncle, Sandberger's species comes nearer still to the present 

 shell ; but, as it is much more elongate and its septa are decidedly wider, I do not 

 think it can belong to the same species. 



15. Orthoceras speciosum, Miinster. PI. XV, figs. 7 ?, 8 — 10. 



1840. Oethocebatites speciosus, Miinster. Beitr., pt. 3, p. 96, pi. xviii, figs. 1 a 



and 3. 



1841. Oethoceeas cinctum, Phillips (not Sow., Min. Conch.). Pal. Poss.,p. 108, 



pi. xli, fig. 204. 

 1849. — OcEANi, d'Orhiffnt/. Prod., p. 54. 



1879. — SPECIOSUM, Giimbel. Geogn. Beschr. Fichtelgebirges, pt. 3, 



p. 498. 

 1888. — CINCTUM, Etheridge. Foss. Brit., pt. 1, Pal, p. 168. 



1888. — SPECIOSUM, Foord. Cat. Foss. Ceph. Brit. Mus., vol. i, p. 94. 



Description. — Shell medium-sized, straight, elongate, slightly tapering. Rate 

 of tapering, 1 : 6 or 1 : 7. Section elliptic, with diameters as 13 : II . Septa very 

 concave, slightly arching, very distant. Height of chambers about one-third their 

 length. Siphuncle large, rather beaded between the septa, central or somewhat 

 excentric. Surface smooth. 



1 1868, Barrande, ' Syst. Sil. Boheme,' vol. i, pt. 3, p. .387, pi. ccxxiv, figs. 24—26; and pi. cccxiv, 

 figs. 1—23, £t. E and F. 



2 Ibid., p. 388, pi. ccxvii, figs. 6, 7; pi. cccxxvii, figs. 19, 20 ; and pi. ccccxxiv, fig. 30—32, fit. D 

 (colony) and E. (Barrande afterwards changes the name of pi. cccxv, figs. 20—32, pi. cccxcvi, figs. 21 

 — 28, to O. spiculum). 



