1914] 
Pearse: Fauna of the Rock Beaches 
77 
Gammariis marinus Leach. Found at Stations 1 and 8 among Asco- 
phyllum and in a pool in the Barnacle Zone. 
Gammarus locusta (Linnaeus) Smith. Abundant at all stations on the 
rock beaches. Mating individuals were seen during the whole period of 
observation, June 8 to 27. 
Gammarus annulatus Smith. This species swarms over the sand beach 
at Station 4, and was observed among stones at Station 10. 
Calliopus laevisculus (Kroyer). Commonly swim in little schools at the 
surface along the rock beaches. On June 24 at 6.30 p. m. the water at the 
dock swarmed with egg-bearing females. 
Jassa marmorata Holmes. Always found in Cladophora artica, an alga 
which grows attached to rocks in exposed situations. 
Amphithoe rubricata (Montagu). Found at Station 7 among Laminaria 
holdfasts, and at Station 12 under Ascophyllum and Fucus. 
Idothea baltica (Pallas). This species was the most characteristic resi- 
dent of the Chondrus Zone on rock beaches. Its color usually matched 
that of the plants on which it rested. Individuals that swam over sand 
beaches were light tan in color. The stomachs of several individuals 
examined on June 25 contained: algal filaments, bits of seaweed, and 
sponge (?). 
Idothea phosphorea Harger. Found only at Station 7 among Laminaria 
roots. 
Jaera marina (Fabricius). Common in all sorts of situations on the rock 
beaches and on the mud flats. 
Chiridotea caeca (Say). The most characteristic inhabitant of the sand 
beach at Station 4; abundant. 
Dyasiylis polita Smith. One specimen taken in a pool in the barnacle 
zone at Station 7. 
Arachnida 
Limulus polyphemus Latreille. Pairs were common on the mud flat at 
Station 14 on June 24, when they were laying eggs. 
Bella marina Packard. This mite was abundant everywhere on the rock 
beaches between tides. 
Agelena naevia Htz. At top of sand beach at Station 4. 
Sallicus scenicus Cl. Taken on the rocks. Stations 1 and 12. 
Attus palustris Peck. Taken on the rocks at Stations 6 and 11. 
Pardosa lapidicina Emerton. Taken on the rocks, Stations 1 and 6. 
Pycnogonidia 
Phoxichilidium maxillare (Stimpson)? Found in a rock cleft filled with 
Hydractinia at Station 8. 
Myriapoda 
Lithobuis juv. One specimen taken on the rocks at Station 12. 
Anislobia maritima Gene. Several observed on the rocks at Station 12. 
