Historic <a href="https://en.wikipedia.org/wiki/St._Anthony_Hall" class="extiw" title="en:St. Anthony Hall">St. Anthony Hall</a> Delta Psi symbol (not currently used by organzation)
University of Pennsylvania Record of 1873
<a rel="nofollow" class="external free" href="http://www.archives.upenn.edu/primdocs/upm/upm7100/1873record.pdf">http://www.archives.upenn.edu/primdocs/upm/upm7100/1873record.pdf</a>