56 



MARINE AND FISHERIES 



6-7 EDWARD VII., A. 1907 



4. Stauroneis ventricosa Kg., 45 x 9. One specimen. 



5. Navicula viridis Kg., 100 x 18, Ribs 7 or 8 to 10 microns. Only one specimen. 



6. Navicula acuminata W.S., 87 x 10, Striae very fine. One specimen. 



7. Navicula cancellata Donk., 52 x 24 to 58 x 26. About 40 ribs, 6 to 10 mic- 

 rons. In Chorda filum collection. 



8. Navicula distans W.S., Fragments. Striae 4 or 5. Two specimens. 



9. Navicula didyma Ehr., 45 x 19 to 70 x 25. Striae about 8. The dimensions 

 are more fully expressed as follows, ranging from 45 x (19:16:19) to 70 x (25:19:25), 

 the middle figure within the bracket indicating the breadth at the middle. Common in 

 the Zostera collection. 



10. Navicula entomon Ehr., 39 x (14:9:14) to 77 x (24:17:24). Stri» 10 or 11. 

 Not so common as N. didyma in the Zostera collection. 



11. Navicula Smithii Breb., 67 x 40 to 70 x 42. Striae 6 or 7. Not common. 



12. Navicula forcipata Grev., 45 x 20. Rare. 



13. Navicula aspera Ehr., 100 x 24 to 120 x 25. Striae from 19 to 13. Somewhat 

 common. 



14. Navicula Baileyana A. S., Var. (?). 63 x 33. Striae 9 or 10. This may be 

 a variety of the following. One specimen. 



15. Navicula marina Ralfs., 80 x 33. Striae 9. One specimen. 



16. Navicula corymbosa Ag., 21 x 3.5 to 27 x 5.5. Striae very fine. Averaging 

 24 X 5. They grew massed on filamentous fronds of gelatine which subdivide like 

 minute branching olive colored seaweed, attached to the piles supporting the wharves. 

 This is a Schizonema of the older writers, and does not appear to be very different from 

 the following species, according to Rabenhorst. Karsten differentiates them more 

 widely. 



17. Navicula ramosissimum Ag., 30 x 4.5 to 30 x 6. Striae 13. Found with the 

 above, of which it may be a variety. 



18. Navicula mollis W.S., 40 x 6. Found sparingly with the above; but whether it 

 is a distinct species or not is a matter of doubt. 



19. Navicula pelliculosa (Breb.) Hilse., 13 x 11. Striae invisible with a one- 

 t\velfth oil immersion lens. 



With further study the last four determinations may require to be revised. A 

 stronger lens and a study of the plants in their habitat may give additional informa- 

 tion. There appears to be a Jack of agreement in important particulars between the 

 ideas held of these species by several of the authorities named above. 



20. Pleurosigma decorum W.S., 220 x 27 to 240 x 35. Oblique striae cutting at 

 about 70°. Oblique striae 12 or 13; horizontal about 15 zb* 



21. Pleurosigma Aestuarii S.W., 97 x 23. Striae just visible in the one-twelfth. 

 This looks also very much like PI. latum, 01. as figured and described by Peragallo. 

 One specimen observed. 



22. Pleurosigma Balticum W.S., 270 x 30. Several specimens seen. 



23. Rhoicosigma (?). 



24. Rhoicosphenia curvata (Kg.) Grun. Var. marinum, 30 x 12 to 35 x 12. 

 Striae 15 ±-. 



25. Achnanthes subsessilis Kg., 56 x 9 to 60 x 20. Striae 8 or 9. Not very rare. 



26. Achnanthes Icngipes Ag., 80 x 33. Large striae 6 in 10 microns with two rows 

 of pearls between each. Small striae about 14. Rare. Found only with the Navicula 

 corpmhosa material. 



27. Cocconeis scutellum Ehr., 20 x 12 to 27 x 18. Rows 12. Very common. 



28. Cocconeis costata Greg., 11 x 6 to 18 x 7.5. Striae about 10. Common. Can 

 hardly be a variety of the preceding species. 



29. Cocconeis ambigua Grun., 12 x 5 to 13 x 7. Doubtful. 



30. Eunotia — ( ?)., 69 x (5 :6 :7 :6 :5). Striae 13. Comes near Eunotia 



pectinalis (Kg.) Rab. ; but the centre is swollen symmetrically both above and below 

 the general arch. That is the ends are about 6 microns, the general length about six 

 microns thick, while the middle swells abruptly to about 7 microns in thickness. 



