in the Neighbourhood of Edinburgh. 191 
in Plate VI., Figs. 6. and '7., where one of them appears in a 
specimen which encloses also the vegetable relic named the Le- 
pidostrobus variabilis.) 
A doubt at first arose whether the fish formed a new species, 
and the more particularly as it approached in character to the 
Palzoniscus angustus of Autun. (See “ Recherches sur les Pois- 
sons Fossiles,” tom. it. page 57.) 
M. Acass1z has, however, referred the specimen to a per- 
fectly undescribed species ; and, in pointing out the small pec- 
toral and the small ventral fins which it possesses, as well as 
the anterior edge of the dorsal fin bemg opposite, or nearly so, 
to the ventrals, he adds, “ what principally characterises it, is its 
elongated form and the thinness of its body, by which it comes 
nearest to the Paleeoniscus angustus of Autun; but, at the same 
time, it differs from all other species belonging to the genus, in 
the much more considerable length of the anterior rays of its 
dorsal and anal fins, and in the considerable size of its tail.” 
With the name which ought to be given to this new species, 
M. Acassiz has declined to interfere. He states, that in a letter 
which I wrote to him, directed to Neuchatel, accompanied. with 
a drawing of the fish, I had, in this instance, successfully attribut- 
ed it to the genus of Paleoniscus; on which account he would 
wish its specific name to rest with myself. An opportunity has 
thus been afforded me, of which I hasten to avail myself, of pay- 
ing the public acknowledgment which I owe for the unwearied 
pains taken by Mr Rosison, General Secretary of the Royal So- 
ciety of Edinburgh, not only in preventing the dispersion of os- 
seous relics so important to geology, but in otherwise affording 
me the greatest assistance in the prosecution of these researches. 
As a tribute, therefore, of the gratitude which I feel for such 
services,.I would beg to name a new species of fish, which, from 
its great abundance, may be almost regarded as characteristic of 
the limestone of Burdiehouse, the Patmoniscus Rosison1.— 
See Plate VI, Fig. 7. 
