No. 394.] NAMES OF CERTAIN FOSSIL FISHES. 789 
having been used by Rafinesque for a genus of mollusks in 
1819. According to Mr. Woodward,! Typodus of Quenstedt 
(1858) is probably identical with Mesodon of Wagner. It is 
therefore accepted provisionally as the generic name of those 
pycnodont fishes which have hitherto been called Mesodon. 
The American species will be 7. abvasus (Cragin), T. dumblei 
(Cope), and T. diastematicus (Cope). 
The genus Catopterus Redfield cannot be retained in the 
sense now given it. It was proposed by J. H. Redfield in the 
year 1837.2, In his paper he states that the name had been 
used by Agassiz originally for a very different fish ; but since 
Agassiz’s Catopterus had been reduced to synonomy, Redfield 
evidently thought that he was at liberty to use it again. Any 
one who has had experience in systematic work has soon 
learned how much confusion this practice produces. Few 
naturalists would now, I think, defend this practice, even 
though they may accept such preoccupied names on account 
of their long standing. Agassiz’s Catopterus is a synonym 
of Dipterus. For the species which have been included under 
Catopterus of Redfield, no other generic name has, so far as I 
know, been proposed. I therefore offer the new name RED- 
FIELDIUS, in honor of William C. Redfield and John Howard 
Redfield, father and son, two of the early students of American 
palzichthyology. The type of the genus will be, as before, 
R. gracilis (Redfield). The other recognized species are œ. 
anguilliformis, R. minor, R. ornatus, R. parvulus, and R. rea- 
fieldi. The change of name of the genus will abolish Catop- 
teride as the name of the family. It may be replaced by 
Dictyopygide from Dictyopyge, the other genus of the 
family. 
The name Eugnathus, by which a well-known group of fossil 
fishes has long been known, must give way to some other term. 
Eugnathus, as a name for fishes, was first employed by Agassiz 
in 1844, the type species being Æ. orthostomus. However, the 
name had been used as early as 1834 by Schonherr for a genus 
1 Cat. Foss. Fishes, vol. iii, pp. 199, 215. 
2 Ann. Lyc. Nat. Hist. N. Y., vol. iv, p. 39- 
8 Poissons Foss., vol. ii, pt. ii, p. 97. 
