No. 394.] NAMES OF CERTAIN FOSSIL FISHES. 787 
the name Rhizodus hibbertt, and the name has clung to them 
ever since. 
Evidently all the species which have been marshalled under 
the name Rhizodus must be placed under Megalichthys of 
Agassiz and Hibbert. The British species are M. hibberti 
Agassiz and Hibbert and M. ornatus Traquair. The American 
. species are M. augustus (Newberry), M. incurvus (Newberry), 
M. lancifer (Newberry), and M. occidentalis (Newberry and 
Worthen). 
What, then, must be done with the species which have been 
masquerading under Megalichthys of Agassiz (1844)? The 
first generic name applied to any of this group of species after 
1844 was Centrodus, given by McCoy! (1848). This, however, 
is preoccupied, having been applied to some fossil elasmobranch 
teeth by Giebel in 1847.2. The next name in order of tithe is 
apparently Parabatrachus, proposed by R. Owen in 1853.3 This 
was given to a portion of the skull of an animal, which Owen 
regarded as batrachian, near Archegosaurus, but which is now 
identified with Megalichthys of Agassiz (1844). The type spe- 
cies is P. colet, but this is now regarded as identical with M. 
hibberti Agassiz (1844). It may not at first thought be pleasing 
to our ideas of propriety to accept this name for a fish, but we 
must remember that one of our common marine fishes bore for 
a long time the generic name Batrachus. 
What specific name is the species described by Agassiz in 
1844 to bear? It cannot be Azbdberti, because the name M. 
hibberti had in 1836 been applied to another species. This will 
furnish some I tion for the disadvantages resulting from 
changes, because the name has been a source of confusion, and 
because Hibbert had nothing to do with it, except to speak of 
it incidentally. The earliest name given in the synonomy of 
the species by Mr. Woodward * is one of Agassiz’s names, mar- 
iWaris® If our conclusions, then, are correct, the fish which 
1 Ann. Mag. Nat. Hist., [2], vol. ii, p. 3- 
2 Fauna Vorwelt; Fische, p. 344- 
3 Quar. Journ. Geol. Soc., vol. ix, p. 67. 
4 Cat. Foss. Fishes, vol. ii, p. 378. 
5 Poissons Foss., vol. ii, pt. ii, p. 96. 
