composting worms

[TxDoc]

Here's a cute photo I took yesterday of one of the eensy beensy new baby composting earthworms I found in my worm bin....he/she is waving hello :

Ahem... I'm not too familiar with worms, I must confess... but where is the head and where is the tail, and what are the two darker 'blurbs' on the worm???