Mushroom

pouihi - I apologize for the delay in answering your question; my ability to communicate has been limited recently.

To respond, the ovate cap enclosed the gills completely. I was unable to see them. Only the cap appears in the pictures of this spotting.

Thanks for the suggestion Lori. My spotting, as you point out, is different in appearance from the "standard" Coprinus comatus appearance in pictures searchable online. Accordingly, I am not ready to declare for certain that this spotting is C. comatus, but it does appear to have been introduced to Hawaii (link below) so it may be.

http://www.fungaldiversity.org/fdp/sfdp/...

Possibly a shaggy ink cap, aka lawyer's wig. It's a bit smooth, but it look young, and may get "shaggier" as it grows bigger.