20 Bulletin Wisconsin Natural History Society [Yol. 11, Nos. 1-2 
(fig. 15), Cancer borealis , Metridium, and Bryozoa; though Mytilus 
(fig. 16), Balanus, and Littorina litorea were abundant, as else- 
where. On June 13 thirty-seven individuals of Cancer borealis 
were counted on several Chondrus - covered rocks in a space thirty 
by fifteen feet at Station 12. Idothea often had a deep purplish- 
red color which matched the Chondrus very closely. Other ani- 
mals that were more or less common in the Irish Moss at low tide 
were: Cliona , Campanula , Serttdaria, Littorina palliata (sometimes, 
Fig. 15. Asterias forbesi on Chondrus. 
L. rudis), Purpura, Orchestia, Gamarellus, Amphithoe, Jassa (in 
Cladophora arctica), Carcinides, Cancer irroratus. 
The larger pools in this zone with a rich growth of Corallina . 
Laminaria and other large algae, contained many animals that 
were not found elsewhere. Here Metridium attained enormous 
size (more than 6 inches in diameter), Littorina litorea was larger 
than in other habitats, and giant Asterias abounded. Other resi- 
dents were Modiola, Cliona, Carcinides, Bryozoa, Strongylocen- 
trotus, Henricia, Botryllus, Tubularia, nudibranchs, Pagurus, Jaera , 
Chiton, Acmaea, and Saxicava. Among the small stones and 
