What breed? They are smaller than rest and...

[zookeeptd]

They came from TS and are with in 1 week of same age of rest of my Bantams but lots smaller. In 3rd pic it's the mottled ones. Serama??

 

[americanvalkyrie]

Ancona? This site says they're very closely related to leghorns, and my exchequer leghorn chick has always been lots smaller than most of the others.

http://www.whitmorefarm.com/ancona

The one with the black lacing looks like a sebright or a bantam wyandotte.