CONTENTS. 



Page 

 No. 1. — Reports on the Dredging Operations of the " Albatross " in 1891. 

 XXVII. Preliminary Account of Planktonemertes Agassizii, a new 

 Pelagic Nemertean. By W. McM. Woodworth. (1 Plate.) July, 

 1899 1 



No. 2. — Contributions from the Zoological Laboratory. XCVL' The Anat- 

 omt and Physiology of the Mouth-Parts of the Collembolan, Orche- 

 sella cincta L. By Justus Watson Folsom. (4 Plates.) July, 1899 7 



No. 3. — Studies from the Newport Marine Laboratory. XLII. Longitu- 

 dinal Fission in Metridium marginatum Milne-Edwards. By G. H. 

 Parker. (3 Plates.) October, 1899 43 



No. 4. — Contributions from the Zoological Laboratory. XCVIII. Ovogen- 

 esis in Distaplia occidentalis Bitter (MS.), with Remarks on Other 

 Species. By Frank W. Bancroft. (6 Plates.) October, 1899 ... 59 



No. 5. — Contributions from the Zoological Laboratory. XCIX. Observa- 

 tions on Non-sexual Reproduction in Dero vaga. By T. W. Gallo- 

 way. (5 Plates.) October, 1899 115 



No. 6.— Contributions from the Zoological Laboratory. C. The Photo- 

 biechanical Changes in the Retinal Pigment of Gammarus. By G. 

 H. Parker. (1 Plate.) October, 1899 143 



No. 7. — Contributions from the Zoological Laboratory. No. 105. The 

 Structure and Development of the Antennal Glands in Homarus 

 americanus Milne-Ed wards. By Frederick C. Watte. (6 Plates.) 

 December, 1899 151 



No. 8. — Contributions from the Zoological Laboratory. No. 109. Matura- 

 tion and Fertilization in Pulmonate Gasteropods. By Henry R. 

 Linville. (4 Plates.) May, 1900 213 



