CLASSIFICATION OF DEVONIAN FISHES 439 
well-preserved specimens of Undina and of AMacropoma has con- 
vinced me that these two genera are not much less closely allied. 
All the structural characters, in fact, which have been enumerated 
above among the peculiarities of Undina are equally well marked 
in Macropoma, except that, hitherto, I have been unable to meet 
with the caudal appendage in the latter, and that the teeth are 
more distinct and cylindrical. But further than this, as Dr. Mantell 
originally suspected, and as Professor Williamson has since demon- 
strated, Macropoma exhibits the peculiarity, without a parallel 
so far as I know, among fishes of other families, of having the 
walls of its air bladder ossified. Now, I find good evidence of the 
existence of a similarly ossified air bladder, not only in Undina, 
Fig. 12. Restoration of AZacropoma,. 
but in a well-preserved specimen of a new genus of Ccelacanth, 
from the Lias (described in the subjoined note by Sir Philip 
Egerton), in the Museum of Practical Geology. 
1 Holophagus Gulo. 
Mr. Harrison’s specimen wants the anterior portion from the dorsal and pectoral fins 
forwards, From the insertion of the dorsal fin to the extremity of the tail it measures 114 
inches, and 4 inches in depth. The stomach is distended with a recently swallowed 
Dapedius, and a large coprolite occupies the rectum. The first dorsal fin springs (as in 
Macropoma) from a single disc, resulting from the coalescence of the interneural spines. It con- 
tains eight long, thick, undivided, and multiarticulate rays. They are beset with numerous 
short spines or tubercles. The second dorsal is situated 4 inches behind the first. Between 
the two is seen a strong bifurcate interneural ossicle, which has been displaced forwards from 
ils proper position at the base of the fin. The second dorsal fin contains sixteen rays. The 
anterior ones are short and slender. The succeeding ones are long, broad, and multiarticulate 
but not tuberculate. The base of the fin is obtusely lobate, with a scaly investment. The 
pectoral fins are much mutilated. Judging from what remains of them, and from some 
indistinct impressions, they seem to have been of great size. The anal fin occurs immediately 
