Vol. XXIV, pp. 45-52 February 24, 1911 



PROCEEDINGS 



OF THE 



r c> v 



BIOLOGICAL SOCIETY OF WASHINGTON 



NOTES ON PERCOPSIS GUTTATUS AGASSIZ AND SALMO 

 OMISCOMA YCUS WALBAUM . 



BY WILLIAM CONVERSE KENDALL. 



| Published by permission of George M. Bowers, U. S. Commissioner of Fish and 



Fisheries.] 



At the meeting of the Boston Society of Natural History of 

 November, 18 18, Professor Louis Agassiz gave an account of two 

 fishes obtained by him at Lake Superior, which he regarded as 

 the types of new genera. Regarding one of these Agassiz said 

 (Proc. Bost. Soc. Nat. Hist. IV, 1851, pp. 80-81): "The 

 first of these two new species is a small fish, five or six inches 

 long, in general shape resembling a Leuciscus. It has the adi- 

 pose fin of the Salmonidse, but not the jaws of that family ; these 

 strongly resemble those of the Percoids. In its scales which are 

 serrated on their margins, it also resembles the Percoids. Its 

 characters are sufficiently peculiar to justify the establishment 

 of a new family from this single species. Fossil species with 

 similar characters are found in the Cretaceous formation. This 

 is the second of the old ' fashioned ' fishes, so to speak, corres- 

 ponding in their structure to fossil species, which has been 

 observed in this country. The other, the Lepisosteus, is the only 

 living representative of a large family of fossil species. 



' The existence of these two species has undoubtedly refer- 

 ence to the fact, that America is the oldest extensive continent 

 which has been upheaved above the level of the sea." 



He called the genus " Percopsis on account of its resemblance 

 to the Percoids." 



In his Lake Superior, 1850, Agassiz gives a fuller description 



of the genus and states that his " new genus, Percopsis, is just 



intermediate between Ctenoids and Cycloids: and that is what 



an ichthyologist, at present, would scarcely think possible — a 



13— Proc. Biol. Soc. Wash., Vol. XXIV, 1911. (45) 



