35 
Inter-hyal (/.fy., figs. 5 and 6).—Possibly a sesa- 
moid bone developed in the inter-hyal ligament and not 
homologous with the other segments of the hyoid. This 
bone is incorrectly called by some authors the stylo-hyal— 
a term really a synonym of the pharyngo-hyal, represented 
in most fishes by the hyomandibular. The inter-hyal of 
the Plaice consists of a central bony rod with cartilaginous 
extremities articulating with the hyoid and symplectic 
and inter-operculum, as already indicated. Below the 
attachment of the inter-hyal to the upper epi-hyal is seen 
the prominence which is also connected with the inter- 
operculum. 
Branchiostegal Rays (/7r./.)—There are the usual 7 
of these rays, the first on each side meeting at their free 
extremities, and being closely bound together by strong 
fibrous connective tissue, appear to fuse. They are not all 
attached at the same plane as shown in the figure. The 
first 3 articulate with the cerato-hyal, the iast 4 at about 
the junction of the 2 epi-hyals. The last, however, is 
always attached to the upper or bony epi-hyal. The rays 
have cartilaginous extremities, but otherwise consist of a 
transparent milky coloured bone. The first two cross and 
lie under the others in the living state. 
Kyeless Side. 
The hyoid bar is slightly shorter and not quite so 
robust. The first pair of apparently fused rays are drawn 
over to the eyeless side as shown in the figure. ‘The most 
tonspicuous difference is in the branchiostegal rays, which 
are, except the first, uniformly shorter and not so curved. 
The length and curve are faithfully represented in the 
figure. 
