LEPIDOTUS. 35 



1873. Lepidotus notopterus /, V. ThioUicre, Poiss. Foss. Bugey, pt. ii, p. 15, pi. iv. 



1887. Lepidotus notopterus, W. Branco, Abliandl. geol. Specialk. Preussen u. Thiiring. Staaten, vol. vii, 



p. 382, pi. viii, fig. 5. 

 1887. Lepidotus notopterus, K. A. von Zittel, Haudb. Palaeont., vol. iii, p. 209, fig. 218. 

 1895. Lepidotus notopterus, A. S. Woodward, Catal. Foss. Fislies, Brit. Mus., pt. iii, p. 92. 



Tjipe. — Imperfect fish; British Museum. 



Specific Characters. — A species attaining a length of about 40 cm. Length 

 of head with opercuhir apparatus nearly equal to the maximum depth of the 

 trunk, and occupying about one-quarter the total length of the fish. Snout 

 acute ; cranial roof-bones with few sparse tuberculations ; teeth on moderately 

 long pedicles. Operculum twice as deep as its maximum breadth, which is 

 contained at least three times in the length of the head. Fin-fulcra very large, 

 the principal dorsal fulcra sometimes half as long as the anterior dorsal fin-rays, 

 and three or four directly inserted in the ridge of the back ; the pelvic fins 

 arising much nearer to the anal than to the pectorals ; dorsal and anal fins deeper 

 than long, the former larger than the latter. Scales smooth, very few serrated, 

 but those of the lateral line and sometimes a few anterior flank-scales slightly 

 notched on the hinder margin. 



Description of Specimen. — An imperfect fish lacking most of the head (PL VII, 

 fig. G), obtained by the late Earl of Enniskillen from the Purbeck Beds of 

 Swanage, differs from L. minor in its smaller and more delicate dorsal fin-fulcra, 

 and agrees well, so far as it can be compared, with L. notopterus from the Litho- 

 graphic Stone (Lower Kimmeridgian) of Germany and France. It may therefore 

 be recorded provisionally under the latter specific name. 



Traces of unusually stout ribs are exposed by the removal of the scales in the 

 anterior part of the abdominal region. On the rest of the trunk the scales are 

 in regular order, and the outline of the fish is only marred by the accidental 

 removal of the ventral part of the abdominal region and by slight crushing in 

 front of the position of the anal fin. The principal flank-scales in the abdominal 

 region are slightly deeper than wide, with a smooth and somewhat convex hinder 

 margin ; above and below they are more nearly equilateral ; and the dorsal ridge- 

 scales are acuminate, though not enlarged. The scales in the caudal region are 

 less deep, with a tendency towards the production of the postero-inferior angle ; 

 some of the ventral scales are much wider than deep ; and two of the acuminate 

 dorsal ridge-scales at the origin of the upper caudal lobe are a little enlarged. 

 The scales of the lateral line are pierced at irregular intervals with large pores, 

 and the hinder margin of each scale is notched near the postero-inferior angle. 

 In the dorsal fin only eight rays can be counted, rapidly decreasing in length 

 backwards, where two or three may be missing ; the fulcra are very slender, the 

 longest scarcely exceeding one-third of the length of the anterior fin-ray, and not 

 more than three being directly inserted in the ridge of the back. The position of 



