162 FOSSIL FISHES OF THE ENGLISH CHALK. 
fies. 1, 2). The principal flank-scales are not deeper than broad, and the number 
of the radiating grooves with which they are marked does not exceed eight or 
nine (fig. 3). The ventral scales are sometimes more than twice as broad as 
deep, and their outline is more or less sigmoidal. The number of the radiating 
erooves 1s comparatively few. On some scales these grooves are almost obsolete, 
and there is instead a slight keel extending obhquely upwards and forwards 
from the postero-inferior angle (fig. 4). One large and flattened median scale, 
probably from the anal region, is marked behind by four short radiating grooves 
(see Catal. Foss. Fishes B. M., pl. vin, fig. 1 4). 
A piece of external bone, apparently found associated with the type specimen, 
is marked with coarse, radiating ridges, on which small tubercles or pustulations 
are irregularly arranged. It is not enamelled. 
Horizon and Locality—Zone of Schloenbachia varians : Folkestone, Kent. 
Family PYcNopontips&. 
Most of the remains of Pycnodont fishes hitherto obtained from the English 
Chalk are so fragmentary that they cannot be generically determined. The only 
important specimens are those of Anomeodus. 
Genus ANOMCODUS, Forir. 
Anomeodus, H. Forir, Ann. Soc. Géol. Belgique, vol. xiv, 1887, Mém., p. 25. 
Generic Characters.—Head-bones ornamented with reticulating ruge. Oral 
surface of vomer nearly flat, with teeth of irregular sizes in from three to 
five longitudinal series; splenial dentition restricted to a space considerably 
separated throughout its extent from the thin oral border of the bone, comprising 
one principal series of teeth, flanked within by at least one small series and 
outside by two or more small series; all the principal teeth smooth or with a very 
feeble linear indent. Scales restricted to part of the abdominal region; all 
ornamented with reticulating ruge. 
Type Speciee—Anomeodus subclavatus (Pycnodus subclavatus, L. Agassiz, Poiss. 
Foss., vol. 11, 1833-44, pt. i, p. 17; pt. ii, p. 198, pl. lxxiia, fig. 59), from the Upper 
Cretaceous (Danian) of Maastricht, Holland. 
Remarks.—The Pycnodontide attained their chief development in the Jurassic 
period, and the Upper Cretaceous Anomeodus must be regarded as a degenerate 
member of the family. The teeth differ from those of other genera in not 
extending to the outer border of the splenial bone, and they are very irregular 
in their arrangement. The scales in the only species in which they are known 
