64 H. H. SWINNERTON, 
laginous connection with the hyomandibular. It is continuous, how- 
ever, in front with the pterygoquadrate cartilage, and is formed by 
ossification of the same‘). At its hinder end, the metapterygoid 
bone is separated from the inner face of the hyomandibular by a 
small pad of dense tissue, which strongly suggests a secondary 
articulation. 
The real extent of the pterygo-quadrate cartilage (Fig. B) is con- 
cealed by the single pterygoid. Ventrally there is a small quadrate 
ossification with a long process which overlaps the preoperculum. 
Dorsally and anterior to the pterygoid the cartilage thickens and forms 
a facette for articulation on the ventral surface of the parethmoid. 
In front of this the cartilage thins out, and is replaced for some 
distance by the slender palatine bone (Fig. F pa). The extremity is 
once more cartilaginous, but owing to the reduction of the ethmoid 
region — a process which involves the loss of preethmoid cornua — 
it bears no relation to the same. Probably this is a modification of 
the disartete condition. Dorso-internally this extremity is separated 
from the rostrale (ro) by a semicartilaginous pad (*); ventrally it is 
prevented from articulating directly on the upper end of the maxilla 
by a similar pad (+). 
The articulation of the hyomandibular is limited to that portion 
which is usually related to the sphenotic and prootic; that which pro- 
jects towards the pterotic (0.p) is reduced, and though it practically 
touches this bone it does not articulate therewith. The ventral end, which 
in normal types passes into the symplectic bone, is occupied by a small 
facet for the articulation of the minute cartilaginous stylohyal. Epi- 
hyal, ceratohyal bearing three branchiostegal rays on its outer side, a 
single hypohyal, and an unossified basihyal (Fig. J hy.b) make up the 
remainder of the hyoid arch. 
All the opercular bones are present. 
Both premaxilla and maxilla (Fig. B) are small and edentulous, 
the latter overlaps the former dorsally and enters largely into the 
formation of the gape. Notwithstanding the great length of the man- 
dible the gape is very insignificant. 
The hyosuspensorial apparatus of Galaxias (Fig. C), in harmony 
with the cranium, shows no marked signs of specialization. The sym- 
plectic (sym) is large, the head of the hyomandibular is broad as in 
1) Cf. development of this bone in Gasterosteus, Swinnerton, H. H, 
l. c. p. 545, tab. 28, fig. 9 sym. 
