1896. | NEW YORK ACADEMY OF SCIENCES. 101 
pobranchian. The present writer, among the rest, had believed 
that Dr. Traquair had brought forward a more than strong case 
in his demonstration of the cyclostomian features of the fossil, 
and he was only too willing to accept so important an aid in the 
solving of the puzzle of the Lampreys. He has been, accord- 
ingly, not a little disconcerted to find in one of the specimens 
of Paleeospondylus * in the collection of fossil fishes of Colum- 
bia College, some structural details which are decidedly opposed 
to the accepted view. And he must, therefore, believe that the 
question of the kinships of the Achanarras fossil is still far 
from being solved. The structures referred to appear to war- 
rant the belief that paired fins may have been present, and that, 
on this account, Paleeospondylus could not strictly have been 
a Marsipobranch. 
The specimen in question, shown in the accompanying figure 
(See Plate V, Fig. B, at end of volume) is a small example, 
about 15 mm. in length, poorly preserved as to the caudal region, 
but showing favorably the structures of neck. It is here, as 
will be seen in the figure, that a dusky band may, on either side, 
be graced tailward from the region of the ‘auditory capsules.’ 
These bands, when examined with a glass, are found to resolve 
themselves into a series of ray-like structures, arranged trans- 
versely to the axis of the body, but slightly inclined backward. 
On the right side they are the more clearly seen, and are especi- 
ally noteworthy in the region of the post-occipital (Traquair) 
plates, PO; here they appear in a graded series, RS, snialler in 
front, the largest one taking its origin from the position of the en- 
larged caudal end of the post-occipital. Seven or more can be 
counted; and each element is seen to become thicker distad, 
terminating bluntly. They cannot be said to definitely take 
their origin from post-occipital plates, although they certainly 
appear to, and there is a suggestion that the right occipital plate 
has been formed of metameral elements. The band of ray-like 
structures continues, however, caudad of the pectoral region, 
traceable backward to the region of about one-half the length of 
the vertebral axis. In this hinder region they cannot be dis- 
tinctly followed, although they are clearly present, small in size, 
and but slightly enlarged distally. It might further be said that 
traces of fine ray-like structures have been noted at the side of 
the fossil near the pectoral region, but these at the best are so 
obscure that their presence cannot definitely be determined. 
The exact character of these fin-like structures of Palzeospon- 
dylus cannot, it is evident, be looked upon as entirely conclu- 
nike These had been received through the kindness of Mr. W. T. Kinnear, of Forss, by 
urso. 
