Note on the Sea Urchins of Laguna Beach 



Due to the kindness of Dr. H. L. Clark of Harvard, we are able 

 now to have some clearer idea about the number of species of sea 

 urchins found at Laguna. 



Strongyloceutrotus ptirpiiratiis Stimp 



This is our most common species. It occurs by the hundreds in 

 some of the larger tide pools, such as those near Seal Rocks. Judg- 

 ing from the specimens sent to Dr. Clark, the rather common 

 greenish form, which we supposed to be distinct at first, is simply 

 a younger form of the same species. This greenish form is more 

 often found nearer shore under stones, where quite small individuals 

 are abundant. 



Figure 1. Sirongytocentrotus purpuratus Stimp. Photo by Miss Clency. 

 Figure 2. Stroriyyloceiitrolus franciscanus A. Agassiz. Photo by Hamilton. 



S. franciscanus A. Agassiz 



These larger urchins are not so common as they may have been. 

 Larger specimens may be obtained under rock ledges in deep water. 

 Smaller forms of the same species, which seem to have long reddish 

 spines, may be found in the tide pools, but are not common. 



W. A. H. 



