These two species can be difficult to separate on the undersides.
The differences were based on the correct images in C&P4 & Fleming & are not absolute.
A. amphinuta. C&P4 plate 40/11, plate 60/1 ,& Fleming L182. A. major. C&P4 plate 40/14, plate 60/2 & Fleming L183. (as A catori not L187 which is actually A. norda as stated in C&P4.)