What would Black's Best Move Be in This Predicament?

Just two questions:

Q1) What would Black's best move be in this case?

Q2) What could Black have done to protect the g5 square from the Knight in a way that still fosters development? It seems a "freebie" perch for a Knight when the Fianchetto is employed, and moving the f6 or h6 pawns to cover g5 messes up the King's shelter.

I look forward to receiving any advice.  Thanks!

Hope I posted the chess board correctly.

I'm afraid that does not compute.

Darn. I think I did something wrong in the embedding procedure.The moves didn't appear.

1. e4 c5 2. Nf3 g6 3. Bc4 Bg7 4. Ng5

Presumably he's going to play 4... e6 with the idea of getting in d5.

The real question is why White went on a fishing expedition with the ineffectual 4 Ng5.

What andy said ..e6 protects the f7 square, prepares d5 and attacks the knight as it uncovered the way for the queen from behind it.

Black has an advantage.

4...e6. (a) 5. d3 Ne7 6. O-O O-O is fine for Black. He will play d5 if allowed. (b) 5. Nxf7?? Kxf7 6. Qf3+ Qf6 loses a piece. (c) 5. Nf3 loses a tempo. Black did not do anything wrong and White's Ng5 does not acomplish anything.

Thanks to all.  I see the light now. Much appreciated. Perhaps I was overthinking.

This kind of stuff happens to me all the time in the blitz games I see (~900 rating). I can usually deal with aggressive white moves like the above, but I end up losing on time in decent positions because I have to take time to figure out how to get out of these messes. Maybe that's their point.