TRIASSIC FISHES FROM SPITZBERGEN 
79 
the components indicated by their names, i. e. of the bones covering the cheek of 
primitive Rhipidistids the dorsal part of the preoperculum would be fused with the 
squamosal and the ventral part of the preoperculum with the quadrato-jugal to the 
squamoso-preopercular and preoperculo-quadratojugal respectively. In Mesozoic Coe- 
lacanthids we find, as I have pointed oyt above, that a dorsal part of the squamoso- 
preopercular has become detached secondarily from the other parts of the bone, to be 
then reduced more or less or perhaps in certain cases to fuse with the postorbital. 
There still remains to be made a comparison between the cheek plates of the 
Coelacanthids on the one hand and certain of the bones in the cranial roof of Stego- 
cephalians on the other, but I have found it more convenient to put this off till 
later on in the chapter «Coelacanthids compared with some other fishes and certain 
Tetrapods». 
The shoulder girdle. 
Together with the head of W. sinuosa described above (P. 257) there also 
occur incompletely preserved remains of the dermal bones of the shoulder girdle. Of 
these the cleithral {Cl, PI. 7, fig. 3 ) was, as usual, long and large, but 
nothing else can be said in detail with regard to its shape. The clavicle 
{Id, PI. 7, fig. 3 ) on the other hand, is somewhat better preserved. It 
has a long slender dorsal limb, with which it joins the cleithral, and a 
ventral one which is developed as a rather large plate, lying horizont¬ 
ally and attached to the corresponding plate on the opposite side by 
a median suture. In shape the clavicle thus bears a considerable 
resemblance to that of Rhizodus (Woodward, 1891b, PI. XII, figs. 4, 7). 
Squamation. 
The squamation in W. sinuosa is very incompletely known. All that is preserved of 
it is some detached scales on the specimens P. 257 and P. 255. 
In shape the scales (text fig. 3 o) are oval with the anterior margin rounded and 
the posterior one somewhat pointed. The covered area is considerably larger than the 
exposed one. The latter has a sculpture (text fig. 3 o; PI. 5, fig. 3 ) of numerous rather 
short and at the same time fine longitudinal striae, the middle ones of which are as a 
rule somewhat longer than those situated dorsally and ventrally. 
* * 
* 
Remarks: — As, from a linguistic point of view, the earlier name of this species, 
sinuata, is incorrect, I have altered it here to sinuosa. This name refers to the characteristic 
sinus on the upper margin of the anterior limb of the pterygoid bone. 
Geological occurrence and localities. — W. sinuosa is only known from the 
fish horizon. Identifiable remains of it have so far been found at Mount Congress and 
Mount Andersson. 
Wimania? sp. 
(PI. 9, figs. 2, 3 .) 
As Wimania? sp. I have grouped here a few remains that come from the caudal 
region of a fairly large Coelacanthid fish {P. 253, P. 256). 
Text fig. 3 o. 
Wimania sinuosa. 
Scale from P. 25 y. */,>. 
