44 HUXLEY, ON THE SKELETON OF FISHES. 
like that of the adult Teleostei, while that which obtains m the 
ancient members of the same group is more like that of 
embryonic T¢Jeostei. But it has never yet been shown, either 
that the approximation of a Ganoid to a Teleostean, or the 
more complete ossification of the vertebral column in these 
or other fishes, is a mark of an advance in general organiza~ 
tion. I take this occasion of repeating an opinion I have 
often expressed, that no known fact justifies us in concluding 
that the members of any given order of animals present, at 
the present day, an organization im essential respects more 
perfect (in whatever sense that word may be used) than that 
which they had in the earliest period of which we have any 
record of their existence. 
It may be asked, in conclusion, whether the peculiar 
structure of the tail of the Teleostean tribes is a modification 
of the vertebral column altogether peculiar to them, or 
whether some trace of it is not to be found in other Verte- 
brata. I believe the latter question may be answered affir- 
matively, and that just where so many remnants of piscine 
characters are found, viz., in the Amphibia, there is a most 
interesting representation of this structure. I refer to the 
coccygeal style of the Frog and its allies, which, as Dugés origi- 
nally indicated (and I have had reason lately to satisfy myself 
of the fact), is formed by the coalescence of a styliform ossi- 
fication of the end of the sheath of the chorda with two neural 
arches. Naturally, as there are no fin-rays, there are no 
epiural or hypural apophyses, but otherwise the resemblance 
of the two structures is complete. 
2. On the development of the palato-pterygoid arc and hyo- 
mandibular suspensorium in Fishes. 
On examining the region in which the complex mass of 
bones comprehended under the above name eventually lies - 
in an embryo Gasterosteus, about 4d of an inch long, I 
found in their place a delicate imverted cartilaginous arch 
attached anteriorly by a very slender pedicle to the angle of 
the “facial cartilage” formed by the union of the two 
trabeculz cranii, and posteriorly connected by a much thicker 
crus with the anterior portion of that part of the cranial 
wall which incloses the auditory organ. The crown of this in- 
verted arch exhibits an articular condyle for the cartilaginous 
rudiment of the mandible. Its posterior crus is not, as it ap- 
pears at first sight to be, asingle continuous mass, but is com- 
posed of two perfectly distinct pieces of cartilage applied 
together by their respective anterior and posterior edges. 
The anterior is continuous below with the condyle, but 
