1913] 
Pearse: Fauna of the Rock Beaches 
19 
4 . The Fucus Zone 
The Fucus Zone was present just below the Ascophyllum in 
exposed situations but dropped out completely in protected bays 
(Fig. 6) and was itself replaced by Mytilus and Balanus on iso- 
lated wave-beaten rocks, (figs. 12, 13, 14). The most character- 
istic animals were Mytilus , Balanus, and Acmaea; others which 
commonly occurred were Purpura, Littorina litorea and L. palliata, 
Asterias, Clinoa, Allorchestes, Cancer borealis, Pagurus pubescens, 
and Pholis. Jassa was found in this zone, always in Cladophora 
arctica. 
Fig. 14. Showing Exposed Rocks at East Point (Station 8). 
The left side is toward the open ocean. The Ascophyllum ( a ) and Fucus 
(/) pinch out and are replaced by Balanus (6). 
5. The Chondrus Zone 
Chondrus crispus, commonly known as “Chagreen” or “ Irish 
Moss” formed a thick carpet on the rocks from a little above low 
tide mark to a considerable depth. Here, as in the Ascophyllum 
zone, the vegetation sheltered a great variety of animals; in fact, 
more species were found than in any other zone. Probably the 
most characteristic animals were Idothea baltica, Acmaea, Asterias 
