TRIASSIC FISHES FROM SPITZBERGEN 
IOI 
The anterior limb is rather long and for the most part very low. It is high only 
in the immediate neigbourhood of the posterior limb, with which it is connected along 
the anterior margin of the ridge just mentioned. Still it does not reach the same height 
as .the posterior one, but farthest dorsally a small extent of the anterior margin of the 
ridge is free. The dorsal margin of the limb, as well as its ventral one, is concave. 
From its connecting place with the posterior limb the former margin runs first in a sharp 
concave arch downwards and somewhat forwards, but afterwards in the larger anterior 
part it takes a more straight direction; the latter margin rises throughout its length 
rather gradually forwards and upwards. 
The mandible in A. robusta is preserved in a much more complete condition than 
in W,'sinuosa, and it is plain that its posterior part was distinguished by a considerable 
height, while anteriorly it was comparatively low (text fig. 44). 
The supraangulo-angular (Sang, ang, text fig. 44; PI. u; PL 15, figs. 1, 2) is 
remarkably high, and has a nearly triangular shape. The ventral margin is fairly 
straight, the antero-dorsal one is slightly concave, and the postero-dorsal one is 
slightly convex. The anterior and posterior corners are acute-angled, the dorsal corner 
also forms an angle and projects rather decidedly, but yet it is 
more rounded than the other two. The lateral side of the bone, 
dorsally of the pores of the sensory canal, is sculptured with 
fine striae, running lengthways. 
The dental ( De, text fig. 44; PI. 11; PI. 15, figs. 1, 2) and 
splenial (Spl, text fig. 44; PI. 15, figs. 1, 2) are only preserved in 
fragments; it can be plainly seen, however, that they were com¬ 
paratively low, and without sculpture. Between their posterior 
ends the supraangulo-angular projects anteriorly to a slight extent. The intercoronoideo- 
prearticular ( Icor . pra, text fig. 44; Pis. 11 —-1 3 ; PI. 15, figs, x—2) is large and probably 
had about the same shape as the supraangulo-angular. 
The coronoid is fragmentarily preserved and the precoronoids are unknown. 
The ossification in the ceratohyal (text fig. 46; Cliy, Pis. 12, i 3 , 15) is short in com¬ 
parison with that of Wimania sinuosa and Sassenia tuberculata. On the ventral margin it has 
the usual broad, rounded projection. The epihyal is still unknown. 
The opercular (Op, text, fig. 44; Pis. 11- i 3 ; PL 15) is a large, triangular bone-plate, 
which has an anterior, an upper and a postero-ventral margin; its antero-dorsal corner 
is rather markedly angular, its postero-dorsal and ventral corners, on the contrary, are 
well rounded off. The anterior margin is concave in the upper part, but convex in the 
lower; the dorsal margin is, on the whole, slightly concave; the postero-ventral margin 
is markedly convex in the dorsal two thirds; in the remaining ventral third it is concave. 
The maximum breadth of the opercular is about two thirds of its height. The sculpture 
consists of rather short, horizontal, mutually parallel striae. 
The branchial arches are, as far as their shape is concerned, in the main like those 
. found in IP. sinuosa, although they are more robust. Their number is as yet uncertain. 
The membrane bones on the dorsal side of the copula are most essentially stronger and 
thicker than in any of the Coelacanthids before known, a condition which is obviously due 
to the character of the dentition. 
Text iig. 46. 
Axelia robusta n. sp. 
Ceratohyal ossification. 
From P. i 9 5. 
