478 
Nachdruck verboten. 
Notes on the Vascular System of Myxine. 
By F. J. Coun, University College, Reading. 
With one Figure. 
An examination of the blood vascular and veno-lymphati¢ system 
of Myxine, on which I am at present engaged, has brought to light 
some points of interest of which a preliminary description may now 
be given. 
Each anterior cardinal vein is formed anteriorly by the union of 
a superficial and a deep anterior cardinal vein, these factors being 
undoubtedly homologous on the two sides. The former originates in 
the brain, of which it is the efferent vessel. The latter originates in 
a large irregular sinus, situated between the so-called hyoid arch and 
the gut, at the level of and ventral to the auditory capsule. From 
this sinus the deep vein arises by a double-valved connection. The 
superficial vessel leaves the cranium by a special aperture dorsal to 
the posterior section of the auditory capsule, and posterior and dorsal 
to the vagus foramen. The superficial and deep cardinals course 
backwards for some distance, and lie respectively external and internal 
to the constrictor pharyngis muscle. In my large series of sections. 
what happened then was not the same on both sides. On the right 
side, the superficial vessel penetrated the constrictor pharyngis muscle, 
and fused with the deep vessel to form the “right anterior cardinal 
vein,” which, therefore, is here internal to the constrictor muscle. 
On the left side, however, it is the deep vessel which penetrates the 
constrictor muscle to fuse with the superficial vessel so as to form 
the left anterior cardinal vein (5) lying externally to the constrictor 
muscle. The two vessels then course backwards in the positions 
described for a considerable distance. The fact that their morpholo- 
gical position is different on the two sides makes it impossible to. 
regard them as homologous vessels, although they arise by the union 
of homologous vessels, and their relations to the peripheral veins are 
the same. The only explanation which covers the anomaly is that 
the superficial and deep cardinal veins, connected by anastomoses, 
