308 ACTINOPTERYGII. 
caudal pedicle, the depth of which equals at least half the maximum 
depth of the trunk. 
Form. Sf Loc. Lower Lias : Leicestershire. 
The following specimens are preserved in nodules from Barrow- 
on-Soar:— 
P. 3580. The type specimen, in counterpart. The figure and 
description of the operculum are misleading, this hone 
attaining its maximum width interiorly and tapering 
above, as proved by the next specimen. Enniskillen Coll. 
P. 2007, P. 3580 a. Hinder part of head and the abdominal region 
of a large specimen in counterpart. The operculum is 
well shown, and the pectoral fin nearly complete. 
Egerton <$' Enniskillen Colls. 
P. 2007 a. Specimen much like the type, but wanting the anterior 
half of the head. The fulcra of the dorsal fin are dis¬ 
played, and appear to be relatively larger than in H. latus. 
Egerton Coll. 
P. 7565. Trunk wanting head, and the squamation only preserved 
in impression. Lulcra are conspicuous on the anterior 
margin of the dorsal and pelvic fins ; and the greater 
part of the caudal fin is shown. 
19488. Posterior abdominal and caudal region of a typical specimen, 
showing the greater part of the dorsal, caudal, and pelvic 
fins. The last-mentioned fins seem to arise just in advance 
of the dorsal, though there may be a displacement. There 
is evidence of robust vertebral elements. 
Presented by the Earl of Aylesford , 1845. 
19488 a. Fragment of trunk, showing pleuroeentrum and hypo- 
centrum in transverse section. 
Presented by the Earl of Aylesford, 1845. 
^ Heterolepidotus typicus (Winkler). 
186^ Brachyichthys typicus, T. C. Winkler, Descript. Poiss. Foss. 
Solenhofen (Natuurk. Verhandl. Holland. Maatsch. [2] vol. 5*iv-r), 
p. 53, fig. 9. f ^ 
Type. Imperfect fish; British Museum. 
The type species of the so-called genus Brachyichthys , attaining 
a length of about 0*5. Length of head with opercular apparatus 
about equalling the maximum depth of the trunk, and contained 
four times in the total length of the fish. Operculum nearly as 
