61 
densely calcified, and so is that portion of the lamina at 
the junction of the arms. The remainder or posterior 
part of the bone consists of a very thin plate or lamina. 
The “ inter-clavicle ” is called by Owen, Huxley and other 
anatomists sometimes the uro-hyalt and sometimes the 
basi-branchiostegal, and it is asserted by Cunningham 
that these names cannot correctly be applied to it. The 
term (.e., “‘ jugular’) used by Cunningham is, however, 
itself inadmissible, since it is Hable to be confounded with 
the jugal or with the jugular plates of “ Ganoids ”’—with 
the former of which it can have no possible connection. 
In the Sole, according to this author, it is apphed directly 
to the clavicle and first basi-branchial, and in this differs 
markedly from the Plaice, where it is placed some dis- 
tance from both these bones. Its position in the Plaice 
relative to that of the clavicle is correctly indicated in 
fig. 8, and it is somewhat further removed from the hyoid 
arch. Hence, whatever its position in other Teleosts, in 
the Plaice it is directly connected neither with the clavicle 
nor with the hyoid. In Sebastolobus according to Starks, 
and in Micropterus according to Shufeldt, what seems to be 
the undoubted homologue of the “ inter-clavicle ” articu- 
lates with the hyoid arch and is called by these authors the 
“uro-hyal.” Cunningham’s objection to this term, how- 
ever, seems to be valid, and hence the provisional name of 
“inter-clavicle ’—a bone with which it may not unrea- 
sonably be identified. On the other hand its connection 
in other forms with the hyoid arch indicates that it may 
have been derived from branchiostegal rays, in which case 
if may conceivably be homologous with the jugular 
+The supposed resemblance to the uro-hyal of the bird doubtless 
suggested this homology. Kyle has recently revived this name for the 
bone, but does not seem to be aware that the terms uro- and glosso-hyal 
are too often used as synonyms to justify any separation now. In any 
“case, we consider the term uro-hyal quite inadmissible. 
