On the Structure of Coccosteus decipiens, Afjassiz. 22 



^zo 



it is not always safe to judge from figures and descriptions 

 alone. This much I am, however, entitled to say — that if 

 such a pectoral swimming-organ really does occur in Prof. 

 V. Koenen's species Bickcnsis, that species cannot be referred 

 to Coccosteus, in which no such organ is present. And, again, 

 •if it is present in Brachydcirus hidorsatus, v. Koen., then 

 Brachydeirus is not merely a " subgenus " of Coccosteus, but 

 a genus with a very great distinction indeed. 



List uf Works referred to. 



(1.) Agassiz, L. — "Monographie des Poissons Fossiles du 

 vieux gr^s rouge." JSTeufchatel, 1844-45. 



(2.) Miller, Hugh. — "The Old Eed Sandstone, or Xew 

 Walks in an Old Pield." Edinburgh, 1841, and 

 subsequent editions. 



(3.) Duff, P.—" Sketch of the Geology of Moray." Elgin, 

 1842. 



(4.) Miller, H. — " Footprints of the Creator, or the 

 Asterolepis of Stromness." Edinburgh, 1849. 



(5.) M'CoY, r. — "Systematic Description of the British 

 Palaeozoic Fossils in the Geological Museum of the 

 University of Cambridge." London, 1851-55. 



(6.) Pander, C. H. — " Ueber die Placodermen des devonis- 

 chen Systems." St Petersburg, 1857. 



(7.) Grey-Egerton, Sir P. de M. — " Palasichthyological 

 Notes. — No. 12. Eemarks on the Nomenclature of 

 the Devonian Fishes," Quart. Joiirn. Geol. Soc. 1860, 

 vol. xvi., pp. 119-136. Contains also notes on 

 Coccosteus by Hugh Miller. 



(8.) Huxley, T. H. — " Preliminary Essay upon the Syste- 

 matic Arrano'ement of the Fishes of the Devonian 

 Epoch," Dec. GeoL Survey, x., 1861. 



(9.) Trautschold, H. — " Ueber Dendrodus und Coccosteus,'' 

 Trans. Imip. Buss. Min. Soc, xv., 1880. 

 (10.) KoENEN, A. VON. — "Beitrag zur Kenntniss der Placo- 

 dermen des norddeutschen Oberdevons," Abli. der 

 komyl. Gesellsch. der Wisscnschaftcn zu Guttinycii, 

 XXX., 1883. 



