Class that lists all the types derived from a given type. Taken from http://stackoverflow.com/a/6944605/1292918

DerivedClassEnumerator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace FooProgram
{
    public static class DerivedClassEnumerator
    {
        // Class that list all the types derived from a given type
        // Taken from http://stackoverflow.com/a/6944605/1292918
        
        // - Uses Assembly.GetAssembly(typeof(T)) because the base class might be in a different assembly.
        // - Use the criteria type.IsClass and !type.IsAbstract because it'll otherwise throw an exception
        //    if it tries to instantiate an interface or abstract class.
        // - Child classes must have identical constructor signatures, otherwise it'll throw an exception.

        static DerivedClassEnumerator() { }

        public static IEnumerable<T> GetObjectsDerivedFromType<T>(params object[] constructorArgs) where T : class//, IComparable<T>
        {
            List<T> objects = new List<T>();

            foreach (Type type in Assembly.GetAssembly(typeof(T)).GetTypes()
                .Where(myType => myType.IsClass && !myType.IsAbstract && myType.IsSubclassOf(typeof(T))))
            {
                objects.Add((T)Activator.CreateInstance(type, constructorArgs));
            }
            // If the classes implement IComparable then their objects could be sorted, see Where clause in signature
            //objects.Sort();
            return objects;
        }

        public static IEnumerable<string> GetNamesDerivedFromType<T>(params object[] constructorArgs) where T : class
        {
            List<string> names = new List<string>();

            foreach (Type type in Assembly.GetAssembly(typeof(T)).GetTypes()
                .Where(myType => myType.IsClass && !myType.IsAbstract && myType.IsSubclassOf(typeof(T))))
            {
                names.Add(((T)Activator.CreateInstance(type, constructorArgs)).ToString());
            }
            names.Sort();
            return names;
        }
    }
}