CONTENTS 



PAGES 



1. Mitosis in Giardia microti, by William C. Boeck; with plate 1; 1 



figure in text 1-26 



2. An Unusual Extension of the Distribution of the Shipworm in San 



Francisco Bay, California, by Albert L. Barrows 27-43 



3. Description of Some New Species of Polynoidae from the Coast of 



California, by Christine Essenberg; with plates 2-3 45-60 



4. New Species of Amphinomidae from the Pacific Coast, by Christine 



Essenberg; with plates 4-5 61-74 



5. Cfithidia euryophthulmi, sp. nov. from the Hemipteran Bug, Eury- 



oplithalm'iis convivus Stal, by Irene McCulloch; with 35 text 



figures 75-88 



6. On the Orientation of Erythropsis, by Charles Atwood Kofoid and 



Olive Swezy; with 12 figures in text 89-102 



7. The Transmission of Nervous Impulses in Eelation to Locomotion 



in the Earthworm, by John F. Bovard; with 4 figures in text 103-134 



8. The Function of the Giant Fibers in Earthworms, by John F. 



Bovard; with 1 figure in text 135-144 



9. A Eapid Method for the Detection of Protozoan Cysts in Mam- 



malian Faeces, by William C. Boeck 145-149 



10. The Musculature of Heptanchus maculatus, by Pirie Davidson; with 



12 figures in text 151-170 



11. The Factors Controlling the Distribution of the Polynoidae of the 



Pacific Coast of North America, by Christine Essenberg; with 



plates 6-8; 2 figures in text 171-238 



12. Differentials in Behavior of the Two Generations of Salpa demo- 



cratica Relative to the Temperature of the Sea, by Ellis L. 

 Michael; with plates 9-11; 1 figure in text 239-298 



13. A Quantitative Analysis of the MoUuscan Fauna of San Francisco 



Bay, by E. L. Packard; with plates 12-13; 6 figures in text 299-336 



14. The Neurometer Apparatus of Euplotes patella, by Harry B. Yocom; 



with plates 14-16 337-396 



15. The Significance of Skeletal Variations in the Genus Peridinium, 



by A. L. Barrows; with plates 17-20; 19 figures in text 397-478 



16. The Subclavian Vein and Its Relations in Elasmobranch Fishes, 



by J. Frank Daniel; 2 figures in text 479-484 



17. The Cercaria of the Japanese Blood Fluke Sohistosomu japonicum 



Katsurada, by William W. Cort; 3 figures in text 485-507 



18. Notes on the Eggs and Miracidia of the Human Schistosomes, by 



William W. Cort; 7 figures in text 509-519 



Index 521-529 



