The year is 1848. The place is the Columbian jungle, at the end of a long, hot day. Two naturalists in khaki safari suits and pith helmets are sitting around a table, sorting through the bird specimens they collected that day. They pull a crow-sized raptor from the canvas gunny-sack and place it on the table.
Naturalist 1: "I say! My good man, a striking specimen we have here."
Naturalist 2: "Quite striking, yes! Accipitridae, would you agree?"
Naturalist 1: "Yes, my good man, I do believe it is Accipitridae or some genus thereabouts."
Naturalist 2: "Yes some genus thereabouts, but we'll let the chaps back in London sort through particulars, eh chap? Eh?"
Naturalist 1: "Ha! Indeed! 'Tis the life of the field for us! Striking creature, though, certainly."
Naturalist 2: "Indeed."
Naturalist 1: "Right, well, shall we commence with the description? Keen to take notes, ol chap?"
Naturalist 2: "Right, sir, dictate away, my good man."
Naturalist 1: "Right. Dictation commencing! Medium-size falcon, shot in these Columbian woods on this, the day of June the 5th, the year of our Lord 1848. Got that?"
Naturalist 2: "Got it, dear chap, continue away."
Naturalist 1: "Commencing physical description of the specimen. The bird appears to be forty centimeters from beak to tail. Snow white belly. Feet and beak of rich orange. Back and head of a stormy plumbeous."
Naturalist 2: "Hold up, butch."
Naturalist 1: "Yes? What's the trouble?"
Naturalist 2: "Plumbeous?"
Naturalist 1: "Yes, a head and back of plumbeous gray, what of it?"
Naturalist 2: "That's no plumbeous."
Naturalist 1: "What! Of course it's plumbeous. Look at it: the dull gray color of lead. Plumbeous."
Naturalist 2: "Not in the least, sir. Too dark. It's castor gray, the color of wet muscovite."
Naturalist 1: "Wet muscovite! Are you mad? Has the damp air affected your vision? It's plumbeous or I'm the queen!"
Naturalist 2: "With all due respect, sir, I grew up with plumbeous. I had a plumbeous coat as a child. Our carpets were plumbeous. The soot from the factory in our neighborhood sent plumbeous plumes into the sky, and the soot settled on the houses in a thick plumbous snow. Growing up, I had a dog such the color of plumbeous that when we brought him home as a puppy the only name we could think of for him was Plumbeous. I know plumbeous, sir, and this bird is no plumbeous!"
Naturalist 1: "Right, well, I didn't realize you had such a connection to the subject. I do apologize."
Naturalist 2: "No need sir, really."
Naturalist 1: "Well then. Hmm. Listen, you do agree that there's at least a bit of plumbeous in this bird, eh?"
Naturalist 2: "Sure well of course it's a bit plumbeous. More plumbeous than cinereous, that's for certain!"
Naturalist 1: "Ha indeed. Well perhaps we could describe this bird in such a way as to reflect the fact that, while it's clearly not entirely plumbeous, it does indeed have a bit of the ol' plumbeous upon its plumage."
Naturalist 2: "Sure, I suppose describing this bird in such a manner as to reflect the true fact that its coloration - while not entirely plumbeous - does contain certain pigments that, on a sort of gradient scale from white to black could, with a few extra drops, eventually reach the pigment known as plumbeous."
Naturalist 1: "Excellent! It's settled then. Well negotiated, dear boy. Now then! Take a look at this plover, what should we name him?"
Naturalist 2: "The Entirely-palmated Plover."