Phylum of worm-like (superficial shape) marine animals with (priapulid worms, or "penis worms") with an extensible spiny proboscis.

There are only 17 species. They have been allocated a separate phylum. The one confirmed British species is Priapulus caudatus.

With all the traditional classifications being upturned and the evolutionary place of Pripulada not all that clear (to me) to start with.

Monophyletic Division:  Protostomia
Subdivsion:  Ecdysozoa  (key: ecdysis)
Phyla:  Kinorhyncha*, Priapulida, Locicifera*  (*all microscopic invertebrates)

Basics (Link)