PROF. L. C. MIALL ON A MEGALICHTHYS. 347 
26. On a new SpEcIMEN of MueaticutTuys from the YORKSHIRE CoaL- 
FIELD. By Prof. L.C. Mratt, F.G.S. (Read April 2, 1884.) 
A LARGE and unusually complete example of Megalichthys Hibberti 
was lately found in the roof of the Halifax Hard Bed at Mr. F. B. Hlli- 
son’s Firebrick Works, Idle, near Leeds, by Mr. Andrew Oldroyd. The 
fossil, which was presented by Mr. Ellison to the Museum of the 
Leeds Philosophical and Literary Society, is externally in good 
preservation and but little disturbed ; the ventral surface is upper- 
most, and the pectoral, ventral, anal, and caudal fins can be more or 
less satisfactorily made out. The dorsal surface and vertebral column 
are altogether absent; but nevertheless this specimen gives more 
information concerning Megalichthys than any other which has 
come to my knowledge. Quité unusual pains were taken by Mr. 
Oldroyd to recover every fragment of the fish. ‘The remains measure 
3 feet 84 inches in length, of which the head includes about 10 
inches and the tail about a foot ; 5 or 6 inches appear to be wanting 
from the end of the tail. The fine skull of Megalichihys figured by 
Agassiz in the Poissons Fossiles *, and still in the Leeds Museum, is 
a trifle larger than the corresponding part of the new specimen. 
Megalichthys may therefore have attained a length of from 4 to 5 
feet. 
The skull of the fossil now under description shows the mandible 
and mandibular teeth, a little of the fore end of the snout, the 
opercula and the jugular plates; but no novel feature is thereby 
brought to light. 
The pectoral fins are quite distinct and nearly in the natural 
position. The left fin shows unmistakably the ‘obtuse lobate” 
character previously suspected to obtain in this genus f, but not, so 
far as | know, distinctly seen in any specimen hitherto described. 
Large basal scales or fulera (figs. 2, 3, b, 6.) lie on either side of each 
pectoral fin. 
The ventral fins are abdominal, as in all Ganoids which possess 
them. The right fin is the best preserved, and shows pretty plainly 
the arrangement of the scales, which in turn gives a clue to the 
disposition of the underlying bones or cartilages. ‘The base of the 
fin is invested by large scales, which are continued in a narrow 
patch along the internal or postaxial border (fig. 4 m. pit.); along 
the outer or preaxial border, which meets the other at an acute 
angle, is ashorter series of large scales (p. pt.). The space between 
these two rows is occupied by much smaller scales in many parallel 
series. If we suppose that in Megalichthys, as in other fishes with 
lobate fins, the large scales invest the more rigid, and the small scales 
the more flexible parts, the skeleton of the ventral fin must have 
-* Vol. ii. pl. 63 and 63 a. 
+ Huxley, Mem. Geol. Survey, dec. x. p. 12 (1861). 
