Mary Sue wrote: " It appears that both references site the same source for the published name with a different spelling." Mary Sue and others: I don't know the answer to the question Mary Sue asked, namely which spelling is the correct one. But I can hazard a guess about why there is that ambiguity. The Latin diphthongs ae and oe are sometimes written as so-called ligatures: two letters squashed together into one. When they are written that way, it's sometimes hard to tell if ae or oe is meant. Furthermore, both the spelling caeruleus and the spelling coeruleus are used frequently. So now I'm very curious to see how this one pans out: maybe someone has access to the actual original publication and can tell us what is there. That would be a good start. Jim McKenney