BERTCIDJ3. 
399 
A species attaining a length of about 0 - 3. Length of head with 
opercular apparatus considerably less than the maximum depth of 
the trunk, which nearly equals the length from the hinder margin 
of the clavicle to the base of the caudal fin. Dorsal fin occupying 
nearly one half of the back, comprising 6 very stout, longitudinally- 
ribbed spines and 8 to 10 divided rays, the length of the longest 
spine almost equalling one third the depth of the trunk at its 
insertion ; anal fin with 7 or 8 divided rays preceded by 3 or 4 
v ery stout spines, which gradually increase to a length about 
equalling that of the longest dorsal. Scales very finely and 
delicately pectinated ; the lateral line traversing about the ninth 
longitudinal series from the ventral border. 
In the fossils from the English Chalk recorded below, the super- 
ficial layer of the external bones and scales is frequently destroyed, 
at least in part, producing an accidental smoothness. 
Form, cj- Loc. Turonian and Senonian : Sussex, Surrey, and 
Kent \ 
4014-15. Type specimen in counterpart, described and figured by 
Mantell, op. cit. p. 234, pi. xxxv. fig. 2, pi. xxxvi., and 
by Agassiz, tom. cit. p. 110, pi. xiv d. fig. 1 ; Upper Chalk, 
Lewes. There are clearly four anal fin-spines, of which 
the two foremost are very small and short. Mantell Coll, 
4030-31. Pine specimen in counterpart, figured by Agassiz, ton i. 
cit. pi. xiv a ; Lewes. Mantell Coll. 
4016. More imperfect fish, figured by Agassiz, tom. cit. pi. xiv l>. 
figs. 1, 2; Lewes. Mantell Coll. 
4008. Small specimen, figured by Agassiz, tom. cit. pi. xiv c. fig. 1 ; 
Lewes. Mantell Coll. 
4027. Imperfect small caudal region, figured by Agassiz, torn. cit. 
pi. xiv d. fig. 3 ; Lewes. Mantell Coll. 
4011, -12, -19, -21, -26, -46, -48, 4105, 09, 4242. Thirteen more 
or less fragmentary specimens; Lewes. No. 4019 shows 
8 branchiostegal rays. Mantell Coll, 
^5781. Head and imperfect trunk, the head figured by Dixon, 
op. cit. pi. xxxiv. fig. 1 ; Sussex. Tubercles are shown 
1 Fragments from the Turonian of Bohemia and Saxony, too imperfect for 
specific determination, are also ascribed to this species by A. E. Eeuss, Verstein. 
bohm. Kreideform. pt. i. (1845), p. 12, pi. ii. fig- 2, pi. xii. figs. 1,2; A. Eritsch, 
^pt. u. Fische bbhm. Kreideform. (1878), p. 43, pi. v. figs. 2, 3. 
