86 DE. G. H. FOWLER— BISCATAN PLANKTO: 



EXPLANATION OE THE PLATES. 



Plate 4. 



Fig. 1. Sayitia serratodentata. x 7. 



2. A jaw. X 105. 



3. Tips of two jaws, x 430. 



4. Teeth of the left side^ from the ventral surface. X 210. 



5. Vestibular ridge of the left side, from the ventral surface. The tips only of the posterior teeth 



are shown, x 210. 



6. Dorsal view of the anterior end, showing the coi-ona ciliata. X 24. 



Fig. 7. Sagitta furcata, Steinhaus. Very well preserved, except for a shrinkage inwards of the lateral 

 fields, which carries the anterior fins nearly out of sight, x 3'5. 



8. The same, perfectly preserved, representing the supposed living outline. X 3'5. 



9. The same, badly preserved and dorso-ventrally compressed : the epidermis in the posterior two- 



thirds flattened and loosened, making the fins appear too broad, and forming a lyra-\\ke bridge 

 between the lateral fins. X 3'o. 



10. The same, very badly preserved, violently contracted antero-posteriorly and somewhat compressed 



dorso-ventrally. The epidermis very greatly flattened and corrugated, x 6. 



11. Corona ciliata and eyes, x 60. 



12. A jaw. x60. 



13. Anterior and posterior rows of teeth, from a cleaned specimen, x 106. 



14. Vestibular ridge, ventral view. X 106. 



15. Vestibular ridge, anterior view with teeth in place, x 106. 



Plate 5. 



Fig. 16. Sagitta macrocephala, sp. u. x 9. 



17. The head, from the ventral surface. X 24'5. 



18. The vestibular ridge and posterior teeth of the left side, from the ventral aspect, x 105. 



19. A jaw. x49. 



20. The first and last tooth, and four from the centre, of the posterior row, from a cleaned specimen. 



The thickness of the bar b is also indicated, x 105. 



21. a. The teeth of the anterior row, from a cleaned specimen, seen from the anterior end. b. The 



smallest tooth, from the dorsal surface, x 105. 

 Fig. 22. Sagitta zetesios, sp. n. x4. 



23. Specimen 32 mm. long, probably referable to this species, with an (artificial ?) expansion of the 



epidermis in front of the anterior fin. X 2. 



24. Vestibular ridge of the left side, x 60. 



25. Anterior teeth, from a cleaned specimen. X 105. 



26. Posterior teeth, from a cleaned specimen. x 105. 



27. A jaw. x33. 



rig. 28. Sagitta bipunctata, Quoy et Gaimard. x 3. 



29. A jaw. X 140. 



30. Anterior and posterior teeth of the right side. X 140. 



31. Vestibular ridge, showing position of first and last tooth, x 140. 



