PECTORAL SKELETON OF TELEOSTEANS. 363 
A. Contribution to the Morphology and Develop- 
ment of the Pectoral Skeleton of Teleosteans. 
By 
H. H. Swinnerton, D.Sc., F.Z.S., 
University College, Nottingham. 
With Plate 23, and three Figures in the ‘Text. 
InTRODUCTORY. 
‘Tue following pages contain the results of an investigation 
conducted chiefly on the salmon and the stickleback. These 
types were chosen as representative of lowly and of advanced 
teleosts respectively. The adult sturgeon and developmental 
stages of other teleosts were also examined in order to correct, 
confirm, and extend results. 
The method pursued was that of reconstruction in wax 
from serial sections as described in my previous papers. 
Swirski, Wiedersheim, and Ducret are the only workers 
who have dealt with the same subject during recent years. 
Of these the first alone attempted to reconstruct the pectoral 
skeleton at different stages; the others confined themselves 
to descriptions and to figures of sections. 
Before proceeding to the main body of the paper I should 
like to record my indebtedness to the Research Committee of 
the Royal Society for a grant towards the expenses incurred, 
to Prof. 'I'. W. Bridge and Prof. W.C.M’Intosh for much useful 
material, and finally to Mr. G. A. Boulenger for his kindly 
criticism. 
