76 
ERIK A : SON STENSIO 
the bones mentioned, partly on the gill-arches. Small or even very small teeth, usually 
blunt, are characteristic of the parasphenoid, pterygoid, coronoid, coronoideo-prearticular 
and the plates covering the copula. 
The ventral surface of the parasphenoid has, in front of the centre of ossification, 
as I have shown above, a thickened median part, to which the teeth are limited. Behind 
the centre of ossification its teeth are very sparse and the thickened part is, as we have 
seen, quite absent. 
The pterygoid has the medial surface of the anterior limb funished with teeth practically 
all over. The posterior limb of the same bone also bears teeth to a considerable extent, 
but the teeth do not extend quite as far as to the posterior margin and they are also absent 
farthest dorsally on a surface which corresponds in height to a third of the limb itself. 
It is impossible to make out whether the teeth of the 
branchial arches are free or coalesced at their bases into small 
plates, as is usual in the Coelacanthids. 
The sensory canals of the head. 
The sensory canals of the head are well developed and en¬ 
closed as usual in membrane bones, which they consequently pene¬ 
trate as tubes. The pores have presumably been small. 
Nothing is preserved of the sensory canals of the cranial 
roof and mandibula. On the other hand, as has been partly 
shown above, we find the sensory canals rather well preserved 
on the cheek in the postorbital, lacrymo-jugal and the squamoso- 
preopercular. 
In the fronto-dermosphenotic the infraorbital canal (text 
fig. 25) has probably turned laterally and with this course it 
has presumably left this bone and entered the antero-dorsal 
corner of the postorbital. In the latter bone (text fig. 25; PI. 5, 
fig. 2; PI. 6, fig. 1) it runs first for a short distance in a postero- 
ventral direction after which it takes a directly ventral course 
and reaches the lower margin of the bone not far behind the 
antero-ventral corner. Ventrally of the postorbital it has passed for a short distance 
through a membranous interspace, then penetrated the plate v, and afterwards continued 
through another short membranous interspace, finally entering the lacrymo-jugal, which 
it traverses to the anterior end. 
From the postorbital part of the infraorbital canal there issues posteriorly between 
the lacrymo-jugal and plate v a sensory canal (text fig. 25;^ PI. 5, fig. 4) which immediately 
enters the process on the anterior margin of the squamoso-preopercular and then runs 
downwards and backwards through this bone to the lower margin, just in front of the 
postero-ventral corner. In its continuation ventrally it seems first to have passed a 
membranous interspace and after that to have transversed the posterior part of the 
preoperculo-quadratojugal. It may possibly have also anastomosed with the mandibular canal. 
It can scarcely be doubted that this last-mentioned sensory canal is homologous 
with the similarly situated one in Osteolepsis (Goodrich, 1919). It seems also probable 
Text fig. 29. 
Wimania sinuosa n. sp. 
Urohyal. From P. s 5 y. • */«. 
A. In ventral aspect. 
B. Cross-section at about its 
narrowest part. Note the crista 
on the dorsal surface. 
