The body is pyriform, broadly truncate on the anterior end, in the middle of which rises a papilliform process (Schnabel).
"Marine Protozoa from Woods Hole" by Gary N. Calkins
Papilliform: like a wart or pimple.
"Explanation of Terms Used in Entomology" by John. B. Smith
These spines are at first papilliform, then elongated and round.
"The Mushroom, Edible and Otherwise" by M. E. Hard