REPORT ON FOSSIL FISHES. 41 
the head and the dorsal fin, a series of ossifications whose exact form is not 
easy determinable, though some of them look somewhat v-shaped, and they 
may have served to enclose the aortic trunk. No trace of anything like ribs is 
observable. A little behind the commencement of the dorsal fin distinct 
hzemal arches and spines appear as well as interspinous bones, supporting the 
anal; but they are unfortunately, in the region of the last named fin, somewhat 
confused and mixed up, so that it is impossible to ascertain if its supporting 
ossicles were in double series, like those of the dorsal. Behind the anal, 
however, the hzmal spines are regularly disposed, and when they are seen 
supporting the lower lobe of the caudal fin, they are laterally flatted and dilated 
at their extremities ; further on they are concealed from view by the scales of 
the caudal body-prolongation. 
At the origin of each ventral fin, something like a small triangular pelvic 
bone is observable. 
The pectoral fins consist of very delicate rays, so delicate that, even with a 
powerful lens, it is difficult to decide as to the extent to which they are articu- 
lated. The small ventrals are situated midway between the pectorals and the 
anal, and have their rays a little coarser, as well as distinctly articulated. The 
dorsal fin, pretty well seen in two specimens, is considerably developed, but 
has not the usual triangular acuminate shape prevalent among Paleoniscide ; 
on the contrary, its apex is rounded off, and its posterior rays are proportionally 
somewhat longer than is ordinarily the case. Its rays are tolerably coarse for 
the small size of the fish, bifurcating once towards their extremities, and divided 
by somewhat distant transverse articulations. The complete contour of the 
anal fin is not shown in any specimen, but it is seen to commence opposite the 
middle of the dorsal, and to extend close to the lower lobe of the caudal ; its 
rays, so far as they are exhibited, are similar in character to those of the dorsal. 
The caudal, judging from its appearance in three specimens, seems to be not so 
deeply bifurcated as in the more typical representatives of this family, though 
it is very heterocercal and inequilobate ; its rays, similar in general appearance 
to those of the dorsal, are, however, finely and minutely dichotomised towards 
their extremities. I have not, after most careful examination, been able to 
detect any fulcra on the anterior margin of any of the fins. 
Remarks.—Independently of the apparent nakedness of the body, the 
specific novelty of this little fish is fully attested by the peculiar form of 
the dorsal fin, and seemingly also of the caudal, as well as by the absence 
of fin fulcra; these last considerations being almost of themselves sufficient 
to indicate a new genus. If the body be naked, then not only is a new 
genus requisite, but the occurrence of a Paleoniscoid fish with the 
squamation in a condition almost identical with that of Polyodon, is a most 
interesting fact in connection with certain important structural affinities 
