62 
ERIK A : SON STENSIO 
An especially noticeable fact is that in the species in question as well as in all 
the rest of the Coelacanthids the processus ascendentes of the parasphenoid are wholly 
missing, which is probably the case in Dictj'onosteus too (Stensio, 1918 c). 
A little in front of the basisphenoid in W. sinuosa there appears on the dorsal 
side of the parasphenoid, a shallow, fairly broad, longitudinal furrow, that continues 
backwards in between the ventral processes of the basisphenoid (text fig. 22) and forms 
with its bottom the ventral boundary for the above-mentioned canal in. This furrow 
may suggest that we have here some special formation. One might perhaps at first 
sight feel inclined to accept the canal m and the furrow mentioned as having originated 
in relation to the hypophysis. If now one compares the facts just stated with those 
given above concerning an eventual fenestration of the interorbital wall immediately 
in front of the ventral processes of the basisphenoid, one cannot avoid suspecting that 
in reality it might be a question of a myodome. This suspicion 
gains in probability if one takes into consideration the considerable 
size of the eyeball in all the Coelacanthids, a circumstance that 
makes it probable that the recti muscles of the eye were well 
developed and had extended backwards into the basis cranii. An 
additional support for this view seems to me to be found in the 
fact that the supposed myodome would occupy the same position 
as that of the Actinopterygians, for, as far as one dare judge, 
n. opticus ought to have emerged into the orbit anteriorly to the 
fenestration of the interorbital wall, and the fenestration itself has 
such a position ventrally of the. fossa hypophyseos that it must be 
regarded as coinciding with the place where one would have the 
right to expect the homologue of the canalis transversus of the 
Elasmobranchii (pituitary canal, Allis, 1909a, pp. i 83 —208; 1914a, pp. 225—253); and 
it is, as known, in relation to this canal, as Gegenbaur (1872, pp. 75-^79), Sagemehl (1884, 
pp. 215—217; 1885, pp. 85—87; 1891, pp. 574—575) and Allis (1909 a, loc. cit.; 1914a, 
loc. cit.; 1918a, pp. 241 246) have shown, that the myodome has developed in the 
Actinopterygians. — It thus seems fairly plausible that a myodome should occur in the 
Coelacanthids, though of course not strongly developed. 
Nothing is yet known about the vomeres of W. sinuosa. 
The membrane bones of the cranial roof in this fish have on the whole been 
closely attached to the dorsal surface of the primordial neurocranium. As I have had 
an opportunity of showing above, the posterior part of this surface lies horizontally, 
and for.ms an angle with the anterior, longer, forward sloping part, as is usual in the 
Coelacanthids. 
On the posterior horizontal part we can now observe in 1C. sinuosa two bones on 
each side of the median line (text figs. 19, 20, 21, 25; PI. 4, fig. 1; PI. 5, fig.-1; PI. 6, 
figs. 3 , 4; PI. 7, fig. 5; PI. 8, fig. 1) as in other Coelacanthids. Of these bones the larger 
anterior one (Pa.it) has been considered by previous authors (Huxley, 1866; Reis, 
1888; Woodward, 1891b; o. a.) 1 ) as a parietal, the smaller posterior one as a squamosal 
Text fig. 24. 
Wiiriania sinuosa n. sp. 
Crossisection through the 
parasphenoid. FromP.iSj.^. 
A) Section anterior to the 
centre of ossification. 
B) Section posterior to' the 
centre of ossification. 
q In 1892 Reis on the contrary was of the opinion that the «parietal» and «squamosal» a 
illy fused (p. 20). 
