Invalid Feeders (aka: feeding cups, nursing cups and/or sick feeders)
They came with different shaped spouts,
different shaped / placed handles,
and different shaped overall cups.
With regards to spouts, but depending on the cup's manufacture, the general opinion is that the straight spouts were introduced first and then the curved and shorter spouts were introduced. Of course there are many exceptions. For instance the Isleworth feeder located in the very top row in the middle (with the two wings, one on each side) was actually manufactured in the 18th Century but it had a curved spout.
Another interesting shape is the Kirby Feeding Cup which came in two parts as shown above.
Please look at the Photo Library as it contains an extremely large inventory of wonderfully representative samples to enjoy and compare.