PLATY80MATID2E, 
547 
A small species attaining a maximum length of about 0’12. 
Greatest depth of trunk exceeding its length from the pectoral arch 
to the base of the caudal fin; dorsal margin much raised and angu- 
lated at a very short distance behind the head; ventral margin 
sharply bent, but rounded, immediately behind its middle point. 
Head relatively large, it with the opercular apparatus and pectoral 
arch occupying considerably more than one-third of the total length 
of the fish to the base of the caudal fin ; most of the head-bones 
finely striated, but those of the cranial roof also in part granulated. 
Pelvic fins very small, remote ; dorsal fin arising at a point about 
as far behind the dorsal peak as the distance of the latter from the 
occiput, terminating some distance in advance of the caudal fin; 
anal fin somewhat shorter than the dorsal, but terminating at the 
same point, and both these fins sharply acuminate in front ; caudal 
pedicle long and slender, and the width of the caudal fin at the 
extremity equalling about half the maximum depth of the trunk ; 
rays of median fins finely ornamented with oblique striae. Scales 
finely striated, the striae being parallel, even, and regular, vertical 
on the deeper flank-scales, but oblique on those situated dorsally, 
ventrally, and upon the caudal region ; ridge-scales in advance of 
dorsal and anal fins with irregularly arranged, recurved denticles, 
those of the dorsal margin of the caudal lobe relatively large and 
granulated. 
Form. Sf Log. Coal-Measures: Staffordshire, Lancashire, York¬ 
shire, and Northumberiand ; Midlothian and Lanarkshire. 
P. 237. Much crushed imperfect small specimen, displaying some 
of the asperities upon the ventral ridge-scales ; Knowles 
Ironstone Shale, Fenton, North Staffordshire. 
Weaver-Jones Coll. 
P. 1602-3. Three more typical specimens of larger size ; Fenton. 
One of the two specimens included under the first number 
shows the distant articulations of the pectoral fin-rays, 
and the numerous spines upon the dorsal and ventral 
ridge-scales ; while both this and the third fossil exhibit 
the ornamentation of the median fin-rays. Egerton Coll. 
P. 3499 a. A very small fish exhibiting the dorsal peak and the greater 
part of the caudal fin; also a much crushed larger speci¬ 
men, wanting the median fins; Fenton. The latter 
specimen shows a series of mandibular teeth, and one of 
the pectoral fins with its sparsely jointed rays, which bi¬ 
furcate distally: below the anal region of this fish there 
2x2 
