C++ to C# (struct)

[C# Programming]

Hi.
Could you guide me what the equal of this struct is in C# ?

struct chromo_typ
{
//the binary bit string is held in a std::string
string bits;

float fitness;

chromo_typ(): bits(""), fitness(0.0f){};
chromo_typ(string bts, float ftns): bits(bts), fitness(ftns){}
};

Thanks