66 H. H. SWINNERTON, 
Salmo'), Alepocephalus?) Amia*), the anterior extremity of the 
pharyngobranchial series is in the same transverse plane as the junc- 
tion between the second and third basibranchials, or is even further 
back than this, e. g. Gasterosteus*); but in this fish (Fig. H) it is on 
a level with the front end of the first basibranchial. It is at present 
impossible to give any explanation of this fact, though it may be as- 
sociated with the end to end arrangement of the somewhat elongated 
pharyngobranchials (Fig. K). 
Another peculiar feature is the general tendency to exhibit 
fenestration at the joints; this is best seen between the epi- and 
ceratobranchials of the first and second arches. The fenestrae be- 
tween the epi- and pharyngobranchials seem to be of the same type, 
though they may be due to secondary connection of each of the former 
with the pharyngobranchial belonging to the arch behind. The 
first pharyngobranchial like the first basibranchial (Fig. J) is car- 
tilaginous. 
As in many Teleosts, e. g. Gasterosteus®) and Galaxias (Fig. L), 
there is a break in the continuity of the basibranchials between the 
third and fourth elements; but in this case the corresponding hypo- 
branchials are almost in direct contact with one another. Unlike the 
majority of these fishes the fourth and fifth basibranchials of Cromeria 
are not only well developed but are also fully ossified. The fifth is 
so large (Fig. H br.b.5) that it extends posteriorly beyond the level of 
the hinder extremities of the last ceratobranchials (br. e. 5). 
As already intimated, the branchial skeleton of Galaxias is quite 
normal as regards the relative positions of the dorsal and ventral 
elements. The fourth as well as the first pharyngobranchial (Fig. M) 
is cartilaginous, and all four members of this series, instead of being 
lineally disposed with respect to one another, continue the line made 
by the epibranchials to which they belong. Each is separate from 
its fellows both in ossification and in cartilage. Basibranchials (Fig. L) 
one to three are ossified, and the first is in contact with the large 
1) Parker, W. K., Skull of Salmon, in: Phil. Trans. Roy. Soc. 
London, V. 163, 1873, tab. 8, fig. 9. 
2) GEGENBAUR, C., in: Morph. Jahrb., V. 4, 1878, Supplement, 
tab. 2. 
4) Auuis, E. P., in: Journ. Morphol., V. 3, No. 3, 1897, tab. 23, 
fig. 49. 
3) Swinnerton, H. H., IL. c. tab. 29, fig. 22. 
4) Swinnerton, H. H., 1. c. tab. 28, figs. 14—16. 
