8EMIONOTID.2E. 
91 
as long as the frontals, which are about three times as long as 
their maximum width, very narrow in front, and united throughout 
their length by a nearly straight, only feebly jagged, median suture ; 
tooth-bearing portion of dentary slender, somewhat deepened by the 
sharp downward curve of its inferior border at the symphysis. 
Marginal teeth styliform, but slightly tumid; inner teeth mostly 
larger and obtuse, but on moderately high pedicles; splenial teeth in 
about three irregular, concentric series, largest within; hinder por¬ 
tion of vomerine dentition comprising three widely-spaced pairs 
of large teeth; hinder pterygoid teeth very small. King-vertebrae 
absent. Fin-fulcra large, but those of the median fins slender; 
distance between origin of pelvic and anal fins about two-thirds as 
great as that between the former and the pectoral fins. Scales large 
and smooth; principal flank-scales not much deeper than broad, with 
a close series of long and acuminate denticulations on the hinder 
border, these being represented by a gradually decreasing number 
of equally large and acuminate denticulations on the posterior 
abdominal flank-scales; caudal flank-scales with a much-produced 
postero-inferior angle; dorsal ridge-scales acutely pointed, in part 
conspicuous. 
Form, Log. Oxfordian : Wiltshire and Huntingdonshire. 
P. 7412. The type specimen described by Egerton, loc. cit.; Christian 
Malford, near Chippenham, Wiltshire. The characters of 
the abdominal flank-scales are not shown. 
(?) Presented by S. P. Pratt , Esq. 
P. 7413. Portions of head and trunk of a similar specimen, lateral 
and partly ventral aspect; Christian Malford. The left 
dentary, maxilla, and quadrate are displayed from the 
outer aspect, with other more fragmentary bones; and 
the characters of the squamation are well shown. 
(?) Presented by S. P. Pratt , Esq . 
P. 6839. Fragmentary head and trunk; Peterborough. The skull 
is vertically crushed, displaying the frontal bones and 
the arrangement of the teeth on the vomerine and palato- 
pterygoid bones. The dentigerous portion of the right 
mandibular ramus is detached, and shown of two-thirds 
the natural size from the outer and oral aspects in the 
diagram, fig. 19 (p. 100), where d indicates the dentary, 
and sjol. the splenial element. Several other more or less 
fragmentary bones are isolated. The upper part of the 
operculum, so far as preserved, is smooth; and there 
