Length 26mm. Llŷn, North Wales. March 2016.
1: hyponotum (ventral surface of girdle) is covered with conical, outwardly directed scale-like spicules, often some stained brownish.
2: peripheral margin of girdle has dense, long spines, though not as long as bristles in tufts.
Bristles and spines appear not to grow as fast as general body size as they often look relatively small on large specimens such as this, and much longer relatively on small young specimens.

KEY ID FEATURES and similar species at: 01 Acanthochitona crinita