Mr. A. S. Woodward on Atherstonia. 239 
margin within the test and a definite and clear line of suture 
separates them from the interradial edges. ‘The pairs of 
pores are remote from the interradio-ambulacral suture and 
there is not a vestige of a “ process.” 
The interradial swelling sometimes rises to a blunt, raised 
edge separated by a little space from the peristomial margin. 
This blunt part is doubtless a degenerated “ridge,” and it 
does not appear capable of affording origin or insertion to 
muscular structure. 
It appears that Echinoconus is much lower in the scale of 
Echinoidea with regard to perignathic structure than the 
species of Discoidea, and certainly these are degraded below 
those of Holectypus, which have a feeble yet fairly perfect 
girdle, jaws, and teeth. 
XXVIII.—On Atherstonia, a new Genus of Paleoniscid Fishes 
Jrom the Karoo Formation of South Africa ; and on a Tooth 
of Ceratodus from the Stormberg Beds of the Orange Free 
State. By A. Surra Woopwarp, F.G.S., F.Z.8., of the 
British Museum (Natural History). 
[Plate XIV.] 
THE only remains of Palzoniscid fishes from the Early Meso- 
zoic Karoo Series of South Africa hitherto described or figured 
are some detached scales made known by Egerton * under 
the names of Paleoniscus Bainii and P. sculptus. However, 
through the generosity of the Hon. W. Guybon Atherstone, 
M.D., F.G.8., of Grahamstown, the British Museum is 
now in possession of a nearly complete fish from the Beaufort 
Beds of Colesberg; and it is the object of the present notice 
to describe and discuss the principal characters of this fossil, 
illustrated in the accompanying Plate XIV. figs. 1-3. 
Description. 
The specimen is shown, nearly one half nat. size, in Pl. XIV. 
fic. 1, and a flank-scale of the natural size in fig. 2, while a 
few scales at the base of the dorsal fin form the subject of 
fig. 8. The general form of the fish is well indicated ; but 
the head is much erushed and its precise contour probably 
destroyed, while the extremity of the caudal fin has been 
* Sir P. Egerton, “Note on the Fish-remains from Styl Krantz, South 
Africa,” Trans. Geol. Soc. [2] vol. vii. (1856), pp. 226, 227, pl. xxviii. 
figs, 26-42. 
