Mr. J. W. Kirkby on Remains of Fish and Plants. 267 
a transformation from a reptile into a bird, to show me, first of 
all, the intermediate steps by which the transition of some one 
living or extinct animal from one class into another was effected. 
If they cannot do this (as they certainly cannot), their views 
must be at once rejected as fantastic dreams, with which the 
exact investigation of nature has nothing to do. 
XXIX.—On the Remains of Fish and Plants from the Upper 
Limestone of the Permian Series of Durham. By Jamus W, 
Krirxsy, 
Tae fossils provisionally noticed in this communication have 
been found in the Upper Limestone of the Permian series of 
Durham. The most important of them are the remains of Fish, 
most of which appear to be undescribed. The others, which are 
the least numerous, belong to vegetables. 
Previous to the discovery of these fossils the remains of fishes 
were not positively known to occur so high in the Permian 
series of the district named, the Marl-slate being the chief and 
almost only subdivision in which they had been found. The 
Marl-slate is nearly at the bottom of the series; the Upper 
Limestone is almost at the top, it being the uppermost member, 
with the exception of the Bunter Schiefer, which is unrepre- 
sented in the immediate region where these fossils occur. Hence 
they are amongst the latest—if not themselves the latest—traces 
that we possess of palzozoic Vertebrata. 
The locality where the fossils are found is in a quarry belong- 
ing to Sir Hedworth Williamson, Bart., at Fulwell Hill, near 
Sunderland. The bed in which most of them occur is not more 
than 2 feet thick. It is mostly laminated and very fissile, and 
it varies from a soft, earthy, yellow limestone to one that is hard, 
crystalline, and grey. 
Nearly all the fish are small Paleonisci, the largest of which 
is only 4 inches in length, most of them being less. Fragments 
of a larger fish, apparently belonging to the genus Acrolepis, 
have also occurred, as well as impressions of others, inter- 
mediate in size, which are so obscurely preserved as to prevent 
any decision as to their affinities. 
1. Paleoniscus varians, n. sp. 
Maximum length 4 inches; greatest depth 1 inch or a little 
more. Head somewhat less than one-fourth of the entire length, 
and a little longer than wide; orbit large, and placed well for- 
ward; mouth of medium size; operculum large, and covered 
with delicate rugose ornamentation. Pectoral fins small; ven- 
