Yes I have been worrying about this for a while. They both have similar outline and position of the dark patch on the forewing. I think the difference is that in M. automima the yellow continues along the costa beside the dark patch, https://bold-au.hobern.net/specimens.php?taxid=408624 in Echinocosma catachrysa it does not and the patch is a little bigger/wider/deeper. https://bold-au.hobern.net/specimens.php?taxid=409872 ps I thought I had just discovered NM had misspelled M. automima, but it turns out the error is with BOLD