You're right about the treaty cruisers though, their kind was pretty much wiped out during the war.
http://en.wikipedia.org/wiki/USS_Phoenix_%28CL-46%29
In the battle of Leyte Gulf, Phoenix was a unit of Rear Admiral Jesse Oldendorf's group which annihilated the Japanese Southern Force in the battle of Surigao Strait. Phoenix fired four spotting salvoes, and when the fourth hit, opened up with all of her 6" (152mm) batteries. The target later proved to be Yamashiro, which sank after 27 minutes of concentrated fire from the American fleet. The Japanese also lost Fusō and three destroyers in the battle, and American planes sank Mogami the next day.
Seven of the 18 treaty cruisers were sunk. The first being Houston after the Java Sea. The last being Indianapolis. Three were sunk at Savo and the Northampton and Chicago in separate Solomons actions. 11 survived the war.
Technically, she wasn't, and was.
"Treaty cruiser" is a term given to those ships designed to the limits of the 1922 Washington treaty: 10,000 tons and 8" guns. Total numbers and tonnage were not limited
But those ships were limited by the 1930 London treaty. Limits of 8" cruisers were actually 6:5:4. At this stage the US had only built 8, so there were no real restrictions to the building program (the last of the next 10, Wichita, in 1937, as actually a modified Brooklyn class, built to fill out the allocation).
The UK was right on the limit and had to cancel 8 ships authourised in 1927, 1928, and 1929.
Japan was already building the twelvth, but could complete all authorised ships, swiching to to nominal "10,000 tonners" with 15 6.1" guns in the 1931 allocation. This was not what the round-eyed parties expected (The US had less than half her allocation built but really didn't want to spend money building more cruisers during the Depression, and the UK really wanted smaller 6" cruisers built in larger numbers for her strategic needs)
The London treaty also imposed tonnage limits for 6" cruisers - 143,000 tons total for the US - but as at the time the US only had 10 small preWashington Omaha class, techically the first 8 Brooklyns fell within the London treaty limits.