CONTENTS 



PAGES 



1. Reactions of Various Plankton Animals with Reference to their 



Diurnal Migrations, by Calvin 0. Easterly 1-83 



2. The Pteropod Desmopterus pacificus sp. now, by Christine Essen- 



berg; 2 figures in text 85-88 



3. Studies on Giardia microti, by William C. Boeck; Trith plate 1; 



19 figures in text 89-134 



4. A Comparison of the Life Cycle of CritMdia with that of Trypano- 



soma in the Invertebrate Host, by [rene MeCulloeh; with plates 



2-6; 3 figures in text 135-190 



5. A Muscid Larva of the San Francisco Bay Region which Sucks 



the Blood of Nestling Birds, by O. E. Plath 191-200 



6. Binary Fission in Collodictyon triciliatum Carter, by Robert Clinton 



Rhodes; with plates 7-14; 4 figures in text 201-274 



7. The Excretory System of a Stylet Cercaria, by William W. Cort; 



with 1 figure in text 275-281 



8. A New Distome from Sana aurora, by William W. Cort; with 5 



figures in text 283-298 



9. The Occurrence of a Rock-boring Isopod along the Shore of San 



Francisco Bay, California, by Albert L. Barrows; with plates 



15-17 299-316 



10. A New Morphological Interpretation of the Structure of Noctihica, 



and its Bearing on the Status of the Cystoflagellata (Haeckel), 



by Charles A. Kofoid; with plate 18; 2 figures in text 317-334 



11. The Life Cycle of Echinostoma revolutum (Froelich), by John C. 



Johnson; with plates 19-25; 1 figure in text 335-3S8 



12. On Some New Myriopods Collected in India, in 1916, by C. A. Kofoid, 



by Ralph V. Chamberlin; with plates 26-28 389-402 



13. Demonstration of the Function of the Neuromotor Apparatus in 



Euplotes by the Method of Microdissection, by Charles V. Taylor; 



with plates 29-33; 2 figures in text 403-470 



Index 471 480 



