REPORT ON FOSSIL FISHES. 67 
that they were continued as a distinct row as far as the head. Very strong 
imbricating V-scales are seen along the upper margin of the caudal body- 
prolongation, the sides of which are clothed with minute scales of the usual 
acutely lozenge-shaped contour. 
A thin dark film occupies most of the body space where the scales are not 
preserved, and on this, in the region above the lateral line, are seen, especially 
when the specimen is held in certain directions, certain faint oblique lines 
passing in an upward and backward direction, which seem to indicate the 
vertebral spinous processes. 
The pectoral fin is indicated on the counterpart of the specimen by a 
narrow remnant of its post-axial margin, from which it would seem that it 
nearly equalled the head in length. No traces of the ventrals are discoverable. 
The dorsal commences just behind the highest part of the arch of the back, 
and extends to the tail pedicle; as H. Parki and H. fulcratus, its anterior 
rays become gradually elongated, and remain long posteriorly, so that the 
contour of the fin rises very gradually in front and finishes off behind in a 
rounded flap-like manner. The anal is like the dorsal in general contour, but 
has a shorter base; for though the two fins terminate opposite each other, the 
former commences a little behind the latter. The caudal is largely developed, 
but unfortunately its termination is not preserved. Nevertheless, so far as we 
can judge, it seems to have been non-bifurcated, and without any distinct 
differentiation into upper and lower lobes, there being no sudden shortening 
of the rays as they proceed onwards towards the extremity ; the caudal body- 
prolongation is powerfully developed. 
The rays of all these median fins are very delicate, closely set, distantly 
articulated, and without any trace of dichotomisation. Very distinct remains 
of strong and powerful long spicules occur at the bases of the anterior margins 
of the fins, which I interpret as largely developed fulcra, which are even more 
out of proportion with the delicate rays which form the expanse of the fin than 
in the case of Holurus fulcratus, 
Remarks.—-This strange little fish cannot possibly be confounded specifically 
with any previously described form ; the only question open to discussion is as 
to the genus in which it ought to be placed. The reasons for referring it to 
Holurus are found in the position and shape of the dorsal fin, the non-bifur- 
cation of the caudal, and the want of dichotomisation in the fin rays. The 
strong fulcra ally it somewhat to Holurus /ulcratus, but the ornament of the 
scales is very different from that in the other two species which I include in 
this genus. 
I have already referred to the non-preservation of the scales over a large 
part of the body of this unique specimen, a condition which seems in this case 
at least to have been caused by some process of decay, which has left the fins 
