gill] the umbras 



297 



acters he assigned to the genus Lcnciscus or that truly define the 

 family of Cypr«inids. 



It was not till 1855 that the true relations of the American fishes 

 were partially recognized. Two years previously (1853) Louis 

 Agassiz had, indeed, referred to " Charaxini [Characini] without 

 adipose fin of I. [J.] ]\Iuller, of which a new genus occurs in the 

 fresh waters of our northern and middle as well as western states, 

 with a half a dozen species some of which," he continues, " have been 

 unfortunately described as Leuciscus, Fundulus and Hydrargyra, 

 with which genera they have no affinity, while other new ones have 

 been described by Professor Baird and myself." He concludes : 

 " I shall call this genus Mclannra, from the singular black mark 

 which all species show on the tail." Such is all the information 

 communicated respecting the new genus, and no one could be certain 

 what species were meant. But in 1855 Agassiz interposed a " Note 

 on Melanura Agass." in a " Synopsis of the Ichthyological Fauna of 

 the Pacific Slope of North America," affirmed that Mclannra is the 

 North American representative of the European Umbra, specified 

 the species he would refer to it, and gave a diagnosis of it. The 

 diagnosis contained no characteristic differentiating it from Umbra. 

 It was regarded by Giinther in 1866 as identical with it, and such is 

 now the opinion of all ichthyologists. 



In 1866 A. Giinther gave the name Umbridje to the family recog- 

 nized by \"alenciennes twenty years before and referred all the 

 American forms, under one specific name (Umbra linii), to the same 

 genus as the European fish (Umbra cranicri). The best idea of 

 their relationship may be conveyed by the statement that they are 

 Pikes in the guise of Killiefishes. They have scales with a peculiar 

 ornamentation or structure, and these extend over the head, leaving 

 only the snout and jaws naked (figures 35, 36). 



Fig. 35. — Scale of Umbra. Fig. t,^. — Head of Umbra, from above. 



II 



The results of investigations thus summarized may be summed up 

 in a few words. 



