Black Clam
A Black clam is a vagina on any women of African descent. It is called so because a female vagina looks like a clam and a darker colored ones are called "Black clam".
Jose walks into the Tijuana whorehouse and tells the Madam, "Senora, you have a lot of pretty Latinas in here but I had my heart set on getting some Black Clam." The madam goes to the back and pulls out a dark Panamanian lady of the night. Jose pays the madam $10 and has his share of that sweet Black Clam!