I can't think of much difference in meaning between 'in particular' and 'particularly', but they have a different position and sound which can affect which one is chosen. 1 the cat, mouse and in particular the dog 2 the cat, mouse and particularly the dog 3 the cat, mouse and the dog particularly 4 the cat, mouse and the dog in particular 1/2 - In 1 when 'in particular' is emphasised, it gives a focus to the dog which separates it from the cat & mouse more than 2 does. 3/4 - Putting the word after (rather than before) creates an ambiguity with whether particular(ly) refers just to the dog or all 3, but context will tell you.
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