Gold-rimmed -- Part 2

Okay, so here's the mystery photo from the post called "Gold-rimmed" on 2 February 2019:

 

A few people guessed the identity of this animal correctly.  But if you need a little more help, the images below show broader views: 

 

 

 

This is the Red-striped Barnacle (Paraconcavus pacificus).  Branched feeding appendages (called cirri) extend upward, emerging from between the opercular plates and the gold-rimmed membrane that connects the plates.

 

Stephanie found this Red-striped Barnacle at Dillon Beach on 1 February 2019.  We appreciated hearing about this sighting, as we've been wondering if Paraconcavus would continue to be seen in northern California after the warm-water years of 2014-2016.  

 

This barnacle often grows on sand dollars, so keep your eyes open for it where sand dollars wash ashore.  (Interestingly, Stephanie found this barnacle on a large clam shell.) 

 

Here's one more view of this beautiful barnacle:

 

 

Many thanks to Stephanie for her observation and helping us document a live Red-striped Barnacle north of San Francisco!