Good for you on quarantining new birds!
Those look like Roundworms. 
You can give Valbazen at 0.08ml per pound of weight orally, then repeat in 10 days. This will take care of 
most worms found in poultry (including Roundworms)
Fenbendazole (Safeguard) can also be used.  
For treatment of Roundworms only, dose at 0.23ml per pound of weight, given orally - repeat in 10 days.  If you feel there may be other types of worms, give the Fenbendazole for 5 days in a row.
To be more effective worm in the morning when the crop is empty.  Let them have water of course, but withhold feed for a few hours after they up.
I would continue the full course of Corid at severe outbreak dose for 5-7 days, then step down to preventative dose for another 3-5 days.
You may want to check them for lice/mites as well.
AFTER you finish with the Corid, offer some poultry vitamins for a few days.  I would also give some buttermilk, yogurt or probiotics to help restore the gut too.
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