MARINE DIATOMS OF THE PHILIPPINE ISLANDS 79 



Length, 0.080-0.205; width, 0.011-0.017; lines, 15 in 0.01 mm. 

 The nearest affinity is G . jiexuosa Grunow and less so G. serpentina 

 Ehrenberg, and G. longissima Petit. 

 Type.— Cat. No. 43625, U.S.N.M. 



GRAMMATOPHORA ISLANDICA Ehrenberg 



(Van Heurck, Synopsis, pi. 53, fig. 7.) 



GRAMMATOPHORA MARINA (Lyngbye) Kiitzing 



(Smith, Brit. Diat,, pi. 42, fig. 314; Van Heurck, Synopsis, pi. 53, figs. 10-11.) 



GRAMMATOPHORA OCEANICA Ehrenberg 



(Ehrenberg, Mikrogeologie, pi. 17, fig, 87; pi. 19, fig. 36a; Van Heurck, Synop- 

 sis, pi. 53bis, figs, 15-16.) 



GRAMMATOPHORA PROBATA, new species 



Plate 16, figs. 6-7 



Valve four times laterally constricted, resulting in one central, two 

 terminal, and two intermediate enlargements, which are of equal 

 width, the sinuses between being longer than the enlargements; ends 

 rounded, hyaline; all the rest of the valve surface covered with strong 

 quincimx markings; median line wanting; central area circular, not 

 oval; along each margin fine, short, sharp prickles, extending to (but 

 not around) the rounded ends of the valves; these prickles sometimes 

 entirely absent. In side (girdle) view the two septa are seen to have 

 two soft undulations, the inner ones smaller; ends of the septa 

 slightly enlarged and curved inward toward the girdle line. 



Length 0.045-0.093; width 0.010-0.013; lines 14 in 0.01 mm. 



The difficulties of uniting this with G. punctata Leuduger-Fortmo- 

 rel as figured and described in Diatomees d'Afrique, page 21, plate 4, 

 figure 5, are that the African species is much less constricted, is 

 greatly enlarged at the center, is marked with coarse transverse lines, 

 has prominent oval hyaline areas at the two ends, has a very oval 

 central area, and is ornamented along each side with strong beads or 

 pearls, none of which is true of this species. As to the last, it is 

 hardly supposable that Leuduger-Fortmorel mistook for pearls the 

 delicate prickles of the above by seeing them out of focus. Both, how- 

 ever, are so unlike other known examples of this genus that the 

 supposition of their being the same is admissable. 



Type.— Cat. No. 43626, U.S.N.M. 



Genus GYROPTYCHUS A. Schmidt 



See Actinodiscus Greville. 



