TRIASSIC FISHES FROM SPITZBERGEN 
49 
Holoptychii, Osteolepidi, Coelecanlhidi and Polypteridi. To Holoptychii he then assigns the 
families Holopthychidae and .Rhizodontidae and, with reservation, Onychodontidae ; to Osteo¬ 
lepidi he refers the families Glyptopomidae and Osteolepidae and eventually also Tarrassiidae. 
The geological range and geographical distribution of the 
Coelacanthids, 
The Coelacanthids appeared as early as in the upper Devonian and persisted to 
the upper Cretaceous. Thus, as Huxley (1861) and Woodward (1898a) have pointed out, 
they seem to have existed for a longer time than any other known family among the 
extinct fishes and, as these investigators also emphasized, they have probably remained 
pretty well unchanged at least from tbe Carboniferous period. 
They were rare in Devonian and, as far as one can ascertain, they also had a 
rather limited geographical distribution in this formation. The only species so far 
described, provisionally assigned by Woodward (1898 b) to the genus Coelacanthus, is 
obtained from the neighbourhood of Gerolstein in Germany. According to Jaeicel (1906b) 
however, an additional form is found at Wildungen, and in a letter in 1917 Jaeicel 
tells me that this form is certainly closely connected with the earlier known one from 
Gerolstein, but that it undoubtedly must be considered as belonging to a new genus. 
During the Carboniferous period the Coelacanthids were represented both in 
Europe and North America by a number of species. A Carboniferous or Permian 
species is also known from Madagascar (Woodward, 1910 b, pp. 5—6) 1 ). 
We may very well take it as probable that Coelacanthids were fairly common 
even in Permian time, although at present we only know a little about this, since, 
apart from the above-mentioned species from Madagascar, the geological age' of which 
it not quite certain, we only find one or perhaps a few European species (Woodward, 
1891b, pp. 399:—408). All the Carboniferous and Permian species are described by 
practically every investigator under the generic name Coelacanthus. As has been pointed 
out in the preceding chapter, it is only Reis (1888; 1900) who has suggested the 
generic name Rhabdoderma for the great majority of the Carboniferous forms, while, in 
his opinion, Coelacanthus ought to be restricted to the Permian ones. 
While the Coelacanthids so far found in the Carboniferous and the Permian seem 
to be rather uniform in their development, those in the Triassic appear, .on the other 
hand, to exhibit a little more variation. Besides Coelacanthus the genera Diplurus (New¬ 
berry, 1888, pp. 70—76; Woodward, 1891b, p. 409; Eastman, 1911, pp. 42—45), Graphiurus 
(Woodward, 1891b, p. 409), Heptanema (de Alessandri, 1910, pp. 36 —4 2) and Undina 
(Andersson, 1916, pp. 14—16) are described from the Triassic. It is, however, probable that 
at least some of, or even all, the Triassic species included under the name Coelacanthus will. 
actually turn out to belong to other, and perhaps in several cases even new, genera. 
To the five Triassic genera given a number of new ones are now to be added, 
of which not less than five, described below, Wimania, Sassenia, Axelia, Mylacanthus and 
1 ■ According to later views (cf. Lenoine, 1911, pp. 5—6) this species comes from deposits of lower Triassic age. 
Stensio, Triassic Fishes from Spitzbergen. 7 
