CONTENTS 



Chap. Page 



I. Introduction, Henry B. Ward i 



II. Conditions of Existence, Victor E. Shelford 21 



III. Methods o£ Collecting and Photographing, Jacob Reighard 61 



IV. Bacteria, Edwin O. Jordan go 



V. Blue-Green Algae (Cyanophyceae) , Edgar W. Olive 100 



VI. The Fresh- Water Algae (Excluding the Blue-Green Algae), Julia W. 



Snow 115 



VII. The Larger Aquatic Vegetation, Raymond H. Pond 178 



VIII. Amoeboid Protozoa (Sarcodina), C. H. Edmondson 210 



IX. Flagellate and Ciliate Protozoa (Mastigophora et Infusoria), H. W. 



Conn and C. H. Edmondson 238 



X. The Sponges (Porifera), Edward Potts 301 



XI. Hydra and Other Fresh- Water Hydrozoa, Frank Smith 316 



XII. The Free-Living Flatworms (Turbellaria), Carohne E. Stringer 323 



XIII. Parasitic Flatworms, Henry B. Ward 365 



XIV. The Nemerteans, Wesley R. Coe 454 



XV. Free-Living Nematodes, N. A. Cobb 459 



XVI. Parasitic Roundworms, Henry B. Ward 506 



XVII. The Wheel Animalcules (Rotatoria), H. S. Jennings 553 



XVIII. Gastrotricha, Henry B. Ward 621 



XIX. Aquatic Earthworms and other Bristle-Bearing Worms (Chaetopoda), 



Frank Smith 632 



XX. The Leeches (Hirudinea) , J. Percy Moore 646 



XXI. The Fairy Shrimps (PhyUopoda), A. S. Pearse 661 



XXII. The Water Fleas (Cladocera), Edward A. Birge 676 



XXIII. Copepoda, C. Dwight Marsh 741 



XXIV. The Ostracoda, R. W. Sharpe 790 



XXV. Higher Crustaceans (Malacostraca) , A. E. Ortmann 828 



XXVI. The Water-Mites (Hydracarina) , Robert H. Wolcott 851 



XXVII. Aquatic Insects, James G. Needhara 876 



XXVIII. Moss Animalcules (Bryozoa), Charles B. Davenport 947 



XXIX. The MoUusca, Bryant Walker 957 



XXX. The Aquatic Vertebrates, C. H. Eigenmann 1021 



XXXI. Technical and Sanitary Problems, George C. Whipple 1067 



