REPORT ON FOSSIL FISHES. 45 
externally these scales are sculptured with prominent longitudinal ridges. 
Behind the dorsal fin acutely pointed scales run along the upper margin of the 
caudal body-prolongation in the usual manner. 
No pectoral fin is seen in any of the specimens, and only in one are some 
imperfect remains of a ventral discoverable, this being placed slightly in front 
of the commencement of the dorsal. The dorsal jin commences behind the 
arch of the back and extends to the commencement of the tail pedicle; its 
longest rays have only about half the length of the base of the fin; and as they 
become very gradually elongated in front and remain pretty long behind, a 
peculiarly rounded and proportionally somewhat long-based form of dorsal is 
here produced, which is very different from the high triangular-acuminate 
contour which is prevalent in this family. The anal is somewhat similarly 
shaped, but has a shorter base, for although the termination of its base is 
opposite that of the dorsal, it commences a little further behind. The caudal 
Jin, arising from the lower margin of a powerful body-prolongation, is not 
bifurcated, but assumes a somewhat triangular shape, with the posterior margin 
only gently concave; its anterior rays being comparatively short, and then 
gradually diminishing posteriorly. The rays of these median fins are nowhere 
seen to dichotomise, but become simply attenuated distally ; they are divided 
by articulations which are distant enough to leave the joints larger then broad ; 
externally they are ganoid, and distinctly striated in the direction of their length. 
No fulcral scales are observable on the anterior margins of any of the fins. 
Remarks.—In its non-bifurcated caudal, and rounded non-acuminated and 
proportionally long-based dorsal fin, this remarkable fish, which I adopt as 
the type of the new genus Holwrus, contradicts the definition of the Palzonis- 
cidee given by me in the first part of my monograph on Carboniferous Ganoids ; 
and in the want of dichotomisation of the fin-rays, it also differs from all 
hitherto described genera belonging to this family. The apparent want of an 
ethmoidal prominence over the front of the mouth is possibly due to defective 
preservation ; in other respects the structure of the head is so decidedly 
palzoniscoid, that I feel compelled to retain it in this family. After all, the 
differences in the configuration of the fins are of slender importance compared 
with the cranial osteology, and I am inclined to regard it as more convenient, 
for the present, to substitute a more comprehensive definition of the Paleeonis- 
cidze than to institute a new subdivision in these characters alone. Of much 
greater weight are the deviations in the structure of the head, which we shall 
have to consider in connection with the next genus (Canobius.) 
I have pleasure in naming this species after Mr WALTER Park, Brooklyn 
Cottage, Langholm, by whose zealous co-operation some of the most interesting 
specimens of the Eskdale fishes were obtained. 
Position and Locality—Near Glencartholm, Eskdale, in the Cement-stone 
group of the Calciferous Sandstone series. 
