BUFFALO SOCIETY OF NATURAL SCIENCES 21 
is illustrated another specimen showing the supports of the anal, 
second dorsal and caudal fins. 
As is well known, the dermal rays of the upper or epichordal 
lobe of the caudal fin are supported directly upon the elongated 
neural spines while those of the hypochordal fin are supported by 
interspinous bones. There is, however, some question as to 
whether the large bones bearing the three ossicles which support 
the first and second dorsal fins are interspinous in character. 
Whiteaves thought they were, and in this view he was upheld 
by Traquair (1890, p. 15); and Hussakof (1912, p. 128) in a 
recent figure of a large fish in the New York State Museum 
indicates that the second dorsal fin was supported by three ossi- 
cles articulated to a larger interspinous bone. However, in all 
of the specimens which are at present before me, this does not 
appear to be the case and so far as can be made out from the 
specimens, the first and second dorsal fins are each supported 
by a large club-shaped bone which appears to be attached directly 
to the vertebral centra, as a modified neural spine. Plate 1, fig. 2, 
shows these bones in what is apparently their natural position and 
my assumption that they are, indeed, neural spines is supported 
by the fact that this element of the first dorsal fin bears on its 
upper surface a process (zigapophysis) which is also to be seen 
in the smaller neural spines. The corresponding bone in the 
anal fin is, however, like those supporting the lower lobe of the 
caudal, an interspinous bone. 
I find that the vertebral centra of Eusthenopteron are not, as 
has been supposed, ossified into complete rings. They are rarely 
perfectly preserved. [Each centra is made up of two lateral pieces 
which are not in contact with each other either above or below. 
There is a conspicuous vertical sulcus on each outer surface as 
Text fig. 8. Section of one-half of vertebra. 
is also the case in the exoccipitals. Text fig. 8 is a vertical cross- 
section of one element. It is thickest above and tapers ventrally. 
