IOWA ACADEMY OF SCIENCES 
255 
Willis and passing into the orbit is beyond question the ophthalmic 
artery. It may be a well developed large vessel, or rudimentary, or 
merely vestigial, or apparently, even absent. Tandler is the only one 
who has recognized the occurrence and the homology of this vessel. 
From the antero-median border of the carotid plexus there run one or 
two small branches that soon unite and pass as a single vessel into the 
skull through the optic foramen. Here it unites with its fellow of the 
opposite side, runs anteriorly and after anastomosing with branches of 
the ethmoidal and anterior cerebral arteries forms a meningeal network 
in the dura of the olfactory fossa. 
The other branches of the carotid arteries and of the circle of Willis 
seem to need no additional description beyond that given by Reighard and 
Jennings. It has seemed worth while to describe the vessels that the 
ordinary student finds either undescribed or described so incorrectly as 
to cause confusion. 
