62 FOSSIL FISHES OF THE ENGLISH CHALK. 



this region are much-constricted, delicate cylinders, scarcely longer than deep, 

 without transverse processes, and only strengthened by a few slight longitudinal 

 ridges. The base of each neural arch is a low lamina extending nearly from end 

 to end of the centrum. In the anterior abdominal vertebras this lamina rises into 

 a pair of spinous processes, which seem to bear a sigmoidally-bent, broad, neural 

 spine (a?.). More posteriorly there is only a slender simple spine fixed to the 

 middle or hinder half of the laminar arch. The ribs are antero-posteriorly com- 

 pressed, and each articulates directly with the anterior end of the centrum to 

 which it belongs. Probably sixteen centra bear true ribs ; but the centrum 

 marked c. in fig. 1 has a fixed hasmal arch with spine and is undoubtedly referable 

 to the caudal series. 



The left post-temporal is partly shown in fig. 1 a (ptt.) and clearly impinges on 

 the supraoccipital. It is a thin lamina, longer than broad, externally ornamented 

 with a few tuberculated radiating ridges. Only insignificant fragments of the 

 appendicular skeleton are known. 



Horizons a itJ Localities. — Zones of Holaster subglobosus to Terebratulina gracilis: 

 neighbourhood of Lewes, Sussex. Zone of Holaster subglobosus : Burham, Kent 

 (G. E. Dibley) ; Glynde and Clayton, Sussex. Zone of Micraster coranguinum : 

 Grays, Essex ; Bromley, Kent. Probably Senonian zones : Brighton ; Shalford, 

 near Guildford. 



2. Enchodus pulchellus, A. S. Woodward. Plate XIV, figs. 9 — 11; Text-figure 14. 



1888. Enchodus levesiensis, A. S. Woodward, Proc. G-eol. Assoc, vol. x, pi. i, fig. 6 (errore). 



1901. Enchodus pulchellus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, p. 193, pi. xi, figs. 2, 3. 



Type. — Imperfect head probably from a Cenomanian zone ; British Museum. 



Specific < 'la i meters.- — A species usually about as large as E. letvesiensis, with more 

 slender mandible and more finely ornamented external bones; very few of the 

 ornamental tubercles raised on ridges. Palatine bone produced considerably for- 

 wards in advance of the ethmoid articulation ; maximum depth of mandibular ramus 

 equalling aboul one quarter of its total length; more than six large mandibular 

 teeth, all both slender and little curved. Maximum width of operculum almost or 

 quite equalling its depth; suboperculum triangular, but about twice as wide as 



deep. 



Description of Specimens. — The type specimen in the Egerton Collection (PL 

 XIV, fig. 9) shows the left lateral aspect of the head, imperfect in front. Part of 

 the ornamented left side of the cranium is preserved, while the characteristic 

 mandible and opercular apparatus are exposed. The palatine hone is covered by 



