Hi. If directory listings were enabled at some point, then Alexa could have found the text_content directory so the bot is coming back to reindex.
Code:
> whois 209.237.238.178
United Layer, Inc. UNITEDLAYER-1 (NET-209-237-224-0-1)
209.237.224.0 - 209.237.255.255
Alexa Internet ALEXA-INTERNET (NET-209-237-237-0-1)
209.237.237.0 - 209.237.238.255
Otherwise it could be someone just trying to find a text file, who knows why as it's just text. Nothing in the PhpDig itself creates links directly to that directory.