This section is from the book "How To Cook Well", by J. Rosalie Benton. Also available from Amazon: How To Cook Well.
Boil the terrapins (in boiling water) till the shell can be easily taken off. Dissect them, removing the sand-bags and head (all the rest is good), taking great care to remove the gall, which is found in the centre. The liver is most delicate and delicious. Stew the meat in cold water enough to cover it. When done, just before dishing, add a large lump of butter, rubbed in flour, a little salt, and red and black pepper. Flavor well with good wine, and serve in a covered dish.
This dish requires to be rich in butter, and enough flour should be used to make the sauce quite thick, for the wine thins it.