I may be mistaken but I believe you are still bound by the Lacy Act and have to put the genus and species name on the box. It need not be in huge red ink but I am almost sure it has to be on there somewhere...
Hmmm, I will have to look into that, but until I do I will not write anything on my boxes. If you do write something on your boxes, like "snake inside", then your box will be much more likely that someone will not ship your box.