C' Example Concurrent Collection Implementations

ConcurrentList.cs

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

namespace ConcurrencyTests
{
    public class ConcurrentList<T>
    {
        private List<T> internalList = new List<T>();
        private object listLock = new object();

        public T this[int i]
        {
            get
            {
                lock (this.listLock)
                {
                    T item = this.internalList.FirstOrDefault(e => object.Equals(e, this.internalList[i]));
                    if (item == null)
                        throw new IndexOutOfRangeException("An element with this index does not exist.");
                    return item;
                }
            }
        }

        public void Add(T item)
        {
            lock (this.listLock)
            {
                this.internalList.Add(item);
            }
        }

        public void AddRange(IEnumerable<T> itemsToAdd)
        {
            lock (this.listLock)
            {
                this.internalList.AddRange(itemsToAdd);
            }
        }

        public long Count()
        {
            lock (this.listLock)
            {
                return this.internalList.Count();
            }
        }

        public void Clear()
        {
            lock (this.listLock)
            {
                this.internalList.Clear();
            }
        }

        public ConcurrentList<T> Clone()
        {
            lock (this.listLock)
            {
                var l = new ConcurrentList<T>();
                l.AddRange(this.internalList);
                return l;
            }
        }
    }
}

I wonder if this would work as expected...