20 FOSSIL FISHES OF THE ENCxLISH CHALK. 



specimens ; but wlien complete the length of the longest spine nearly eqnals one 

 third the maximum depth of the trunk, and its length seems to be scarcely exceeded 

 by that of the foremost of the articulated rays, which were prol)ably about eight 

 to ten in numl)er. The anal fin arises slightly nearer to the pelvic pair than to the 

 caudal fin and is provided with four fluted spines (PI. Ill, fig. 4), which gradually 

 increase in length so that the longest is about as large as the longest dorsal spine. 

 Beyond the spines only fragments of articulated rays are seen in PI. Ill, fig. 4; 

 but another specimen in the British Museum (no. 4903()) clearly exhibits seven 

 supports for such rays in its anal fin. The caudal fin has never been completely 

 observed, but some specimens show that it must have been forked. 



The scales are large, thin, and deeply overlapping ; and those of the flank are 

 deeper than broad. Their hinder border is gently rounded and very finely 

 pectinated, but the greater part of their exposed face is delicately rugose. Their 

 inner face sometimes exhibits a few tuljerculations. The numl)er of scales in a 

 transverse series on the flank of the abdominal region is about 11. The course 

 of the lateral line is marked l)y a smooth triangular prominence on each scale 

 of the series traversed, which is the ninth from the ventral border in the 

 abdominal region (PL III, fig. 1, //.). 



Horizons and Localities. — Zones of Holuster suhijJohosns to Tfrchratnliua gracilis : 

 neighbourhood of Lewes, Sussex ; neighbourhood of Burham, Kent. Zone of 

 Holaster snhglohosus : Folkestone and Dover, Kent. Zone of Tctrhrahilina (/racilis : 

 Cuxton, Kent. Zone oi Micraster cor-testuJinarinm : Purley and Guildford, Surrey. 



2. Hoplopteryx superbus (Dixon). Plate IV, figs. 2, 3; Plates \, VI ; Plate 

 VII, figs. 2—5. 



1850. Beryx superhus, F. Dixon, Geol. Sussex, p. 372, pi. xxxvi, fig. 5. 



1887. Hoplopteryx superhus, J. W. Davis, Trans. Roy. Dublin Soc. [2], vol. iii, p. 514. 



1888. Hoplopteryx superhus, A. S. Woodward, Proc. Geol. Assoc, vol. x, p. 328. 

 1901. Hoplopterj/x superhus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, p. 403. 



Ti/pe. — Imperfect fish from one of the Turonian zones ; British Museum. 



Specific Characters. — A large species, attaining a length of about 45 cm., with 

 fins apparently similar to those of H. lewesiensis but the trunk slightly more 

 elongated and the scales relatively larger and more strongly ornamented tlian in the 

 latter species. Operculum less than twice as deep as broad. Lateral line travers- 

 ing the sixth or seventh longitudinal series of scales above the ventral l)oi'der. 



Description of Specimens. — The type specimen in the Dixon Collection (B. M. 

 no. 25959), from Southeram, near Lewes, shows the greater part of the trunk with 

 remains of the median fins, and is inipei'fectly r('])resented of half the natm-al size 



