443 
of Edinburgh, Session 1876 - 77 . 
Robert Walker states was described by Professor Goodsir in 1838 
before a meeting of the Literary and Philosophical Society of St 
Andrews, and which, according to Mr Walker, he characterised as 
closely allied to Palceoniscus , but differing from it “ in wanting the 
scaling or false rays along the anterior ray of the fins, and also in 
the dorsal fin being opposite the anal.”* In this specimen the 
dorsal is, indeed, nearly opposite the anal (as in others of the same 
genus as well as species), but, on close examination, fulcra are dis- 
tinctly observable. I have not been able to obtain Professor 
Goodsir’s description, or even to ascertain exactly where it is to be 
found, but as it appears to have been published only in a provincial 
newspaper, the generic name Catopterus must remain with the 
Triassic semi-heterocercal Lepidosteids, to which it has been applied 
by the Messrs Redfield. 
Geological Position and Localities. — From the Calciferous Sand- 
stone series. In ironstone nodules from the shore at Wardie, near 
Edinburgh ; on the shore near Pittenweem, in Fifeshire, in the col- 
lection of Mr J. W. Ivirkby ; in a compact grey limestone at Corn- 
ceres near Kilrenny, collected by the late Professor Goodsir. 
Rhadinichthys tenuicauda, sp. nov. Traquair. 
Length, about 2J to 3 inches ; form slender, narrowly tapering 
posteriorly. Head bones sculptured externally, with closely set 
flexuous ridges ; dentition not visible. Scales rather large for the 
small size of the fish, and especially large on the sides of the abdo- 
men, becoming smaller on the back and towards the tail. The 
posterior margins of the scales are denticulated, their external sur- 
faces nearly smooth along the sides of the body and on the tail 
pedicle, but along the back, especially between the dorsal fin and 
the head, they are marked by a few rather prominent oblique ridges ; 
a similar ornamentation, though rather finer and closer in character, 
makes its appearance also on the scales along the ventral margin. 
The pectoral fin is small ; the non-articulation of its stouter rays 
seems to prevail over a less extent of the fin than is usual in this 
genus. The ventral is still smaller. The dorsal and anal are of 
medium size, and nearly opposite each other ; their rays are fine 
* Trans. Geol. Soc. of Edinburgh, vol. ii. pt 1. (1872), p. 124. 
