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 

 Palasoniscus angustus of Autun. (See " Recherches sur les Pois- 

 sons Fossiles" torn. ii. page 57.) 



M. Aoassiz 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 being 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 Palaeoniscus 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. Agassiz 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 Palasoniscus ; 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 Robison, 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 Pal^ioniscus Robisoni.— 

 See Plate VI., Fig. 7. 



