276 GEOLOGICAL DISTRIBUTION 
entirely with that of the teeth of the living Lepi- 
dosteus osseus. (PI. 27% Figs. 1, 2, 3.) 
Smaller Sauroid Fishes only have been no- 
ticed in the Magnesian limestone, forming about 
one fifth of the total number yet observed in 
this formation. Very large bones of this vora- 
cious family occur in the lias of Whitby and 
Lyme Regis, and its genera abound throughout 
the Oolite formation.* In the Cretaceous for- 
mations they become extremely rare.f They 
illustrated with engravings, from which the larger teeth in our 
plate are copied. (PI. 27, Fig. 11, 12, 13, 14). The smaller 
figures, PI. 27, Fig. 9, and PI. 27“, Fig. 4, are drawn from 
specimens belonging to Dr. Hibbert and the Royal Society of 
Edinburgh. 
In this memoir, Dr. Hibbert has also published figures of some 
curious large scales, found at Burdie House, with the teeth of 
Megalicthys, and referred by M. Agassiz to that Fish. Similar 
scales have been noticed in various parts of the Edinburgh Coal 
field, and also in the Coal formation of Newcastle-on-Tyne. 
Unique specimens of the heads of two similar Fishes, and part 
of a body covered with scales, from the Coal field near Leeds, 
are preserved in the museum of that town. 
Sir Philip Grey Egerton has recently discovered scales of the 
Megalicthys, with teeth and bones of some other Fishes, and also 
Coprolites, in the Coal formation of Silverdale, near Newcastle- 
under- Line. These occur in a stratum of shale, containing shells 
of three species of Unio, with balls of argillaceous iron ore and 
plants. 
* The Aspidorhynchus, from the Jurassic limestone of Solen- 
hofen, (PI. 27“, Fig. 5), represents the general character of the 
sauroid Fishes. 
t The Macropoma is the only genus of Sauroid Fishes yet 
found in the Chalk of England. 
