MARINE DIATOMS OF THE PHILIPPINE ISLANDS 125 



NAVICULA WEISSFLOGII A. Schmidt 



Plate 27, fig. 7 



(Schmidt, Atlas, pi. 12, figs. 26-32; Van Heurck, Synopsis, Supp., pi. B, fig. 21.) 



This species is here represented by a rather wide variety (see my 

 figure) , in which the beading is finer and more closely set than in 

 the type. It is probably the same species as N. diversa Greville 

 (Diat., vSo. Pac, pi. 4, fig. 14, 1863) which if so, would replace the 

 above name (1873). Only an examination of Greville's type speci- 

 men can determine this, as his figure is manifestly somewhat fanciful. 

 This is another species found in both Campeche Bay and the Philip- 

 pine Islands. 



NAVICULA YARRENSIS Grunow 



(Schmidt, Atlas, pi. 46, figs. 1-6.) 



This striking species of massive sculpture occurs in a fossil state 

 in Hungary, as well as now living at widely separated localities, 

 United States Atlantic Seaboard, Samoa, Kiel, Germany, and the 

 Philippine Islands. 



NAVICULA ZOSTERETI Grunow 



(Grunow , N. Ung. Gek. Diat., pi. 2, fig. 23; Schmidt, Atlas, pi. 47, figs. 42-44.) 

 Genus NITZSCHIA Hassall 



NITZSCHIA ALATA Leuduger-Fortmorel 



See N. campechiana Grunow. 



NITZSCHIA BISCULPTA, new species 



Plate 28, figs. 1-2 



Valve broadly elliptical, slightly constricted at the middle, with 

 rather acute, wedge-shaped ends; finely marked with close beading 

 arranged in quincunx lines, the sculpturing being bisected longitu- 

 dinally by a narrow ragged, median, hyaline line, slightly curved , 

 toward the dorsal side; the half on the ventral side of this line is 

 further marked by a prominent overlay of short, more or less vermi- 

 form shining dashes; wanting on the dorsal half; costal band on the 

 dorsal margin small and finely cross-barred, interrupted by a nodule 

 in the sinus of the median constriction. 



Length, 0.133-0.170; width, 0-050-0.062; decussating lines, 12-13 

 in 0.01 mm.; costae of dorsal band, 5.5-6 in 0.01 mm. 



This curiously marked diatom, belonging to the N. panduriformis 

 group, is rather abundant in the Philippine Islands. I have found 

 it also at Hilo, Hawian Islands. It bears a slight resemblance to 

 N. nicobarica Grunow. 



Type.— Cat. No. 43666, U.S.N.M. 



