TRIASSIC FISHES FROM SPITZBERGEN 
269 
in the proximal parts of the lepidotrichia. Both on the dorsal and anal fin the number 
of endoskeletal radials corresponds almost or exactly to that of the lepidotrichia. The 
epidotrichia of the ventral fins are unjointed, at least to a rather great extent. We find 
here, as is shown by thes facts, a process undoubtedly going on towards the development 
of the type of fin described in Perleidus, which is, 
already pointed out, characteristic of the higher 
ganoids and Teleosts. Colobodus s. str. thus forms a 
natural link between the more primitive genera pQ 
Catopterus and Dictjropyge on the one hand and 
Pleidus, with possibly Dollopterus and Meridensia, on £ x| 
the other. Under these circumstances there seem 
to be no arguments at all in favour of separating 
Perleidus and the forms that agree with it and esta¬ 
blishing a special family for them, as one might 
at first feel called upon to do. 
Text fig. 
D sp v, 00 
Colobodus maximus Dames. 
Some observations on the family 
Catopteridae; a summary. 
After a specimen belonging to the Palaeontological 
Institute at Upsala Vi- Sensor)' canals shaded. 
Ant, antorbital; Dsph, dermosphenotic; Ext, extra¬ 
scapular; Fr, frontal,- Na. ptr., nasalo-postrostral: 
Pa, parietal; R, rostrals; So, supraorbital; Stemp. 
it, supratemporo-intertemporal; na, external nasal 
From the account given above it ought to 
be obvious that the genera Catopterus, Dictyopyge, 
Colobodus s. str., Perleidus and Dolopterus are on 
the whole closely related to one another and that 
they form together, as far as we can judge at present, 
a rather uniform group. Because of this I see no 
reason to maintain a family Colobodontidae any longer, 
but consider it most convenient to group all the 
mentioned genera in the family Catopteridae. Whether 
Meridensia also belongs to this family is a question 
that cannot yet be answered. Provisionally, however, 
it seems as if we might include this genus as well 
among the Catopterids (cf. Stolley, 1920, pp. 83,84). 
The distinguishing features of the family Cato¬ 
pteridae may under these circumstances be summa¬ 
rized as follows. The shapes of the fishes vary rather considerably ; sometimes they are rather 
slender, sometimes more deep-bodied. The head has a blunt snout with a weak indication of 
a rostrum. The eye far forward. Mouth large, extended far back. External membrane bones 
of the head ornamented with ganoine. On the ethmoidal region there lies posterior to the pre- 
maxillaea transverse series of rostrals, and behind them there follows a median unpaired rather 
large nasalo-postrostral, and on the right and left side of this an antorbital bone. The latter 
bone and the nasalo-postrostral surround the nasal apertures of either side. The nasalo-post¬ 
rostral includes the nasal elements and the interrostrals of both sides, and sometimes also 
one or a couple of median rostral elements. The maxillary is low beneath and high behind 
Text fig. 87. Colobodus maximus Dames. 
Sketch after a specimen belonging to Redakteur 
Konig of Heidelberg. Vx- Sensory canals shaded. 
Md, mandible; Mx, maxillary; Op, operculum; Po, 
preoperculum; Rbr, radii branchiostegi; Sop, sub¬ 
operculum. 
