yeir Specuiien of Cladad us i-hirhi. — CUnijxjle. 5 
cult and in part impossible to interpret them with much con- 
fidence. Owing to the fracture and the weathering already 
mentioned, nothing can be seen of the hj'oid apparatus, which 
must, therefore, be entirely omitted. Farther back, however, 
can be seen manifest traces of five branchial arches. The 
ceratobranchial cartilages are in most cases complete on one 
side or the other, growing more distant posteriorly. In one 
or two places the connection of these with the epibranchials 
can be detected; but, from the position of the fish, these are 
for the most part concealed in the stone. 
A large basibranchial plate occupies the space between the 
ceratobranchials, and extends somewhat behind the fifth of 
them. As the first and second of these are in advance of the 
front of this plate, it is not improbable that it has been pushed 
backward during the process of fossilization. 
No trace of hypobranchials is visible. 
The Shoulder Girdle. Amid the confusion of broken car- 
tilages, plates and fin rays, it is not eas}' to be certain of de- 
tails in this region. Conspicuous, however, in the midline is 
the coracoid plate formed by the fusion of the right and left 
coracoid cartilages, both of which are indistinctly seen in po- 
sition. Their extensions to the scapular region cannot be posi- 
tively identified, but are almost certainly represented b}' sev- 
eral fragments occupying their positions. 
The Fins. The pectoral fins are the only ones that are vis- 
ible in the fossil, and these are only imperfectly displayed; 
but by comparison several facts can be discovered. In the 
first place, each fin consists principally of about twenty to 
twenty-three strong, cartilaginous, unjointed rays, thick at 
the base, and becoming gradually thinner and flatter toward 
the margin. Most of these, excepting the few foremost, curve 
gentl}" backward from their bases, then run at right angles 
to the body (when the fin is extended), sweeping again 
backward as they approach the edge. They all deplo}-^ on the 
edge, those in front without any membranous margin, but the 
hinder part of the fin possesses a distinct region that is desti- 
tute of rays, being occupied by short trichinosts. 
The first few rays form the front edge of the fin by running 
out close to one another, but behind these the rays diverge 
and taper on the margin ; and between them come in inter- 
