166 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 4, NO. 4. 
Plates 4 and 5 are those showing the right and left faces of 
still another specimen, in which is seen not only the base of the 
inserted portion of the spine, but which shows that it is supported 
by a second ray of the spine laying directly back of and fitting 
accurately into the sulcus on the posterior part of the first ray, a 
fact that was unknown at the time the type was described. The 
faces of this second ray are covered with tubercles, as is the first 
ray, and agrees with it in every particular. This second ray of 
the spine has about the same, general thickness of the first ray.' 
The inserted portion terminates in a bulbous end, and penetrated 
the body of the fish some distance lower than the termination of 
the first ray, while its distal end was probably approximately acute 
and terminated at a point about midway between the distal ter- 
mination of the first ray and a line about even with the angle on 
the anterior face of that ray. The anterior margin of the second 
ray should have an angular face to fit into the sulcus noted on 
the posterior face of the first ray. The markings on the posterior' 
face of the second ray are unknown at this time. This specimen 
shows the gradual contraction at the base of the right and left 
faces of the first ray, bringing the base to almost an acute termina- 
tion. (Dr. Eastman's supposition, that the inserted portion of 
the spine tapered gradually towards the base is thus proved cor- 
rect.) The bulbous termination of the second ray and the manner 
in which it fits against the acute termination of the first ray 
shows the very strong support given thereby. Both the right and 
left faces of the two rays show the tubercles peculiar to the species 
to extend to the extreme ends of the inserted portion, where, 
however, they are much smaller and rather more numerously dis- 
posed than on the exerted portion. Assuming that the specimens 
that we have secured in the aggregate are of the average size, a 
reconstruction of a spine from them would show a length of about 
sixteen and one-half inches from the base of the inserted portion 
to the apex, a very formidable weapon of either offense or defense, 
and one that could have belonged only to a fish of very large size. 
Associated with the specimen on Plates 4 and 5 is to be seen 
a fairly well preserved specimen of the fossil tooth Paloromylus 
greenei, the only case we know of in which any portion of a tooth 
has been found with any of the spines so far collected, and, while 
there is probably nothing in this association to positively identify 
