MARINE DIATOMS OF THE PHILIPPINE ISLANDS 117 



NAVICULA PUDENS, new species 



Plate 26, fig. 3 



Valve, narrow elliptical, with rounded ends; crossed by coarse rows 

 of beading, the rows as well as the beads in each row not closely set; 

 rows strictly transverse except near to the ends of the valve; outside 

 bead in each row larger than the rest, thus forming a marginal series 

 around the valve and slightly distant from the hyaline rim; longitu- 

 dinal median area one-fifth the width of the valve, slightly broadened 

 at the center to form an oval hyaline median area; rhapke inclosed 

 by parallel ridges on each side, straight, the middle ends widely 

 separated. 



Length, 0.047: width, 0.014; 7 lines in 0.01 mm. 



This is practically the same diatom as the unnamed form in 

 Schmidt's Atlas, plate 7, figure 49, from Campeche Bay. It also is 

 closely related to N. sejuncta A. Schmidt (Nordsee Diat., pi. 1, fig. 18, 

 and Schmidt, Atlas, pi. 212, figs. 9-10). 



Type.— Cat. No. 43657, U.S.N.M. 



NAVICULA PUELLA A. Schmidt 



(Schmidt, Atlas, pi. 12, figs. 13-15; pi. 69, figs. 15-25.) 



The making this a variety of N. splendida Gregory in Fricke's 

 Index is open to doubt, at least in the case of plate 12, figures 13-14, 

 and plate 69, figure 15, above. It is another diatom common to both 

 Campeche Bay and the Philippine Islands. 



NAVICULA PUGIO, new species 

 Plate 26, fig 4 



Valve convex, narrow lanceolate, tapering from the middle to the 

 acute apices; markings of diagonally directed parallel rows of coarse, 

 round or oval beads, the rows, as well as the beads in each row, some- 

 what distant; a flaring central stauros extending almost to the sides 

 and depressed below the beaded portions of the valve; rhaphe not 

 reaching the apices, its middle terminations almost touching and 

 slightly bent to one side. 



Length, 0.110; width, 0.017; 5 lines in 0.01 mm. 



This very narrow and coarsely marked diatom belongs to the 

 N. aspera Ehrenberg group. It is somewhat rare. 



Type.— Cat. No. 43658, U.S.N.M. 



NAVICULA PULVULENTA, new species 



Plate 25, fig. 3 



Valve long, hexagonal, with straight, parallel sides and wedge- 

 shaped ends ; slightly convex and slightly depressed transversely across 

 the middle; at the margin the valve bends quickly downward to 

 form vertical sides which join with the girdle; a thin hyaline line 



