There's no equivalent for that in C#. The generics in C# are quite different to those in Java in various ways, including the way covariance and contravariance work.
You could have a generic method (or generic type) with a constraint on the type parameter like this:
public void Foo<T>(IList<T> list) where T : SomeClass
or
public class Foo<T> where T : SomeClass
... but Type itself (the .NET equivalent of Class<T>) is non-generic, so there's no way of saying "This is a list of types which extend A".
If you give us more information about what you're trying to achieve, we may be able to help you more.