= 
254 Dr. R. H. Traquair—New Coal-measure Paleoniscide. 
preoperculum is broad and triangular, the lower one narrow. 
I see no markings on these opercular bones save a few concentric 
strie. The maxilla is of the ordinary paleoniscoid shape, but in 
none of the specimens are its markings clearly shown. The 
mandible is comparatively short, and is ornamented by prominent 
ridges which run obliquely forward so as to touch the upper or 
dentary margin at very acute angles. 
The scales are small, rhombic, and with the usual paleeoniscoid 
mode of articulation. It is extremely difficult accurately to make 
out the character of the outer surface, which seems to be ornamented 
with excessively minute and faintly marked ridges and furrows, 
bearing obliquely downwards and backwards over their surface. 
Remarks.—I place this strange little Paleeoniscid, whose specific 
characters are so strongly marked, only provisionally under 
Rhadinichthys; and probably a new genus will ultimately have to be 
established for it, characterized by the more than usually prominent 
snout and the dorsal being exactly opposite the anal fin, characters 
in which I must own it differs from the typical species of Rhadi- 
nichthys. 
Geological Position and Locality.—Coal-measures. The best speci- 
mens I have seen are in the collection of Mr. John Plant, of the 
Royal Museum, Salford, who obtained them from Colleyhurst near 
Manchester; others, less perfect, are in the collection of Mr. Ward, 
of Longton, who collected them from the Deep-Mine Ironstone of 
that locality. Burnley, Lancashire, collected by Mr. G. Wild. 
I have pleasure in naming this species after Mr. Plant, who has 
always been most liberal in affording me access to the specimens of 
Coal-measure Fishes in his collection. 
Acrolepis Wilsoni, sp. nov., Ward, MS. 
Exposed surface of scale 3 inch in height by 3% in breadth: 
rhombic, closely covered with small pits about ;4;imch in diameter, 
which in the middle of the area are arranged quite irregularly, but 
above and below are disposed in three or four regular lines parallel 
with the upper and lower margins respectively. _ The surface 
between the pits is minutely fretted with excessively delicate grooves, 
only perceptible by aid of a lens. 
The well-developed covered area projects upwards in an angular 
process, the articular spine is strongly marked. 
Remarks.—The scale described above was collected by Mr. E. 
Wilson, F.G.S., from the Yoredale Shales of Turnditch, near Belper, 
Derbyshire, and recognized as new by Mr. Ward, of Longton, 
through whose intermediation it came into my hands for description.t 
The shape of the scale indicates Acrolepis as its genus, but the 
pecularity of its markings entitles it to specific distinction, and 
accordingly, at the request of Mr. Ward, I name it Acrolepis Wilsont. 
1 Since the period here referred to, the scale has come into the possession of the 
British Museum. 
