32 Bulletin Wisconsin Natural History Society [Vol. 11, Nos. 1-2 
2. On the sandy mud below the large boulders Mya, young and 
adult, was abundant. Nereis virens lurked beneath the stones 
which supported Balanus, Mytilus, and Littorina litorea. The 
latter also wandered freely over the rather firm beach between the 
stones. Carcinides was common everywhere. Floating eel-grass 
or other debris was often stranded here in considerable quantity. 
3. Beyond the small stones and boulders there was a rather 
barren stretch of beach with occasional tufts of small ulva-like 
alga which grew attached to little pebbles. Carcinides and Idothea 
occurred here. 
Fig. 29. The Top of the Mud Beach at Station 14 (Fig. 1), Showing 
the Absence of Algae on the Rocks. 
4. Next came a zone of scattered eel-grass. Nassa and its egg 
cases was abundant in certain places; Mytilus formed enormous 
beds; Littorina litorea clung to the eel-grass or any other available 
object (fig. 30); Carcinides of large size were abundant every- 
where; Cancer irroratus was occasionally seen. The mud was 
filled with a little worm (Lumbri conereis?) which formed long 
tubes. Limulus (fig. 31) was breeding at the time the observa- 
tions were made. Many mollusc shells were neatly perforated — - 
the work of boring snails. 
5. The lower parts of the flats supported a thick growth of eel- 
grass. The dominant animal here was Carcinides; many large 
females with eggs were seen. Littorina litorea was abundant; 
Crago (females bearing eggs), Limulus , Idothea baltica, Jaera, and 
