Disclaimer: This is my first bike and I'm just going through the tune-up procedures for the first time, so forgive me in advance for being a total noob.

I recently removed the gas tank to replace the spark and am having a hard time identifying two hose connections and hoping someone can help. There is one hose that comes from the gas tank in addition to the gas line and fuel emission line, and another line that comes from the upper left hand side of the carb. I know one of these hoses connects to the vacuum line on the right side of the carb. I have no idea where the other one goes. I've attached an image with annotations.

Any help is appreciated!  

Appreciate it! Does the vent line attach to a valve in the same spot on the other side? Can't seem to locate it..