PLATE L. 



Fig. 



1. Early stage in the development of Nephthys, October 23rd, 1897. X 100. 



2. An older stage of the same date. X 100. 



3. Specimen captnred a few days later (October 28th) showing certain alterations of the 



head and body. X 100. 



4. Head of Eulalia bilineata, Johnst. Enlarged. 



5. Outline of the head and anterior region of Eumida sanguinea, from St. Andrews. 



Enlarged. 



6. Young Phyllodoce, from St. Andrews, June 15th, 1898. Enlarged. 



7. Dorsal cirri of a variety of Phyllodoce lamelligera, Linn., from Plymouth. Enlarged. 



8. Head of Phyllodoce rubiginosa, De St. Joseph, from a Plymouth specimen. Enlarged. 



9. Head of Trypanosyllis zebra, Grube, from Plymouth. Enlarged. 



10. Tail of the foregoing. Enlarged. 



11. Pelagic male Autolytus (= Polybostrichus) . Enlarged. 



12. Larval Nereis (Alitta) virens, from St. Andrews Bay, October 26th. X 50. 



13. Older larval stage apparently of the same form, from St. Andrews. X 45. 

 14 and 15. Dorsal and front views of larval Nereis, from St. Andrews. X 100. 



16. Post-larval Nereis (Alitta ?), September 26th, St. Andrews. X 40. 



17. Head of Nereis irorata, Grube, from Plymouth. Enlarged. 



