400 
ACTINOrTERYGIT. 
on the ridges of the cranial roof ; and the hinder border 
of the post-temporal is pectinated. Dixon Coll. 
25827. Imperfect small fish, figured by Dixon, op. cit. pi. xxxvi. 
fig. 1; Sussex. Dixon Coll. 
25839. Imperfect trunk, figured by Dixon, op. cit. pi. xxxvi. fig. 3 ; 
Sussex. Dixon Coll. 
25841, 25863, 25869, 25905, 25907, 25912-13, 25915-16, 
25918-19. Mne fragmentary specimens, two being in 
counterpart; Sussex. Dixon Coll. 
49862-63, 49870-71. Four imperfect specimens, the first displaying 
the greater part of the vertebral column and part of 
a pectoral fin ; Upper Chalk, Lewes. Capron Coll. 
P. 1948,-a,-b. One fragmentary small fish, a block containing two 
imperfect small fishes, and a large head; Sussex. 
Egerton Coll. 
P. 3977. Small head and fragment of abdominal region ; Sussex. 
Enniskillen Coll. 
P. 5420. Fine head, with some anterior scales, shown of the 
natural size in PI. XVI. fig. 4; Lewes. The cranium 
exhibits some of the deep cavities between the tuber- 
culated or pectinated ridges on its roof. The proportions 
of the orbit are clear, the greater part of the cheek being 
covered by a chain of suborbital plates (s.o.). The orbital 
margin (c.o.) of each of these plates is everted and tuber- 
culated, while the lower margin, immediately above the 
maxiUa, is distinctly serrated; the middle part of the 
plates is quite smooth, and forms a deep channel for the 
reception of the slime-apparatus. The mandibular sus- 
pensorium is nearly vertical, the gape of the mouth 
extending just behind the eye. The long, slender pre¬ 
maxilla {pmx.') bears traces of clustered minute teeth 
throughout its length; and the maxilla {mx.) im¬ 
mediately above it is quite smooth, with a triangular 
expansion , behind. A large supramaxilla {s.mx.) is 
ornamented with tuberculated ridges on its outer face, 
and is excavated in front as if for the reception of a 
smaller anterior supramaxilla. The dentary (d.') bears 
numerous, clustered, minute blunt teeth, like those of the 
premaxilla; its outer face is deeply channelled below for 
the slime-canal, and the longitudinal ridge above the 
