Characters suggestive of L. corrugis: white felting on and somewhat corrugated quality of cap. Characters suggestive of L. volemus: crowded gills, color of gills and stipe. Latex was not particularly bitter, nor did it smell particularly fishy. Wiped it off my finger before it could stain.
Id by mycologist Joe McFarland.
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid ('latex') if cut or damaged. Like the genus Russula, with which they are grouped in the family Russulaceae, their flesh has a distinctive brittle consistency.