4 
ACTINOPTERYGII. 
and opercular apparatus are distinct ; and the delicate 
cylinders forming the vertebral centra are well shown. 
Purchased , 1894. 
P. 7090. Imperfect impression of large Bsh, and greater portion of 
trunk of a smaller specimen. The latter displays the 
delicate vertebral centra and the thin scales marked with 
fine longitudinal striations. 
Presented by Harry M. Becher, Esq., 1894. 
P. 7095. Distorted specimen, artificially polished. Purchased, 1 894. 
lo Ly copter a may also probably be referred the so-called Prolebias 
davidi (H. E. Sauvage, Bull. Soc. Geol. France, [3] vol. viii. 1880, 
p. 4o2, pi. xiii. figs. 5, (>). It is described as abundant in a whitish 
shaly limestone “ belonging to the Tertiary formations of Northern 
China.’ It is not represented in the Collection. 
Synopsis of Cretaceous and Tertiary Families of Isospondyli. 
All characterised by presence of intermuscular bones and absence of 
fulcra on fins. 
1. Margin of upper jaw formed by maxilla and 
premaxilla. Precoracoid arch present. 
(a) Parietal bones usually meeting in 
the middle line, and squamosal 
bones well developed. 
Marginal dentition comparatively 
well-developed ; opercular ap- 
paratus complete, and bran- 
chiostegal rays numerous, with 
gular plate Elopida: (p. 7). 
Mouth small, and marginal dentition 
feeble or abseut ; opercular ap- 
paratus complete, but branehio- 
stegal rays few, and no gular 
Pkte Axuulid.*: (p. 59). 
Opercular apparatus incomplete, 
with 10 to 20 branchiostegal 
rays, but no gular plate ; scales 
In03R ' c 'like in structure . Osteoglossidje (p. 73). 
\°> oupraoccipital usually more or less 
completely separating the parietal 
bones in the middle line; squa- 
mosal bones much reduced, and 
pterotic region prominent; no 
gular plate. 
