MARINE DIATOMS OF THE PHILIPPINE ISLANDS 37 



BIDDULPHIA CORNUTA (Greville) Mann 



(Micro. Journ., 1861, pi. 8, fig. 8; Van Heurck, Synopsis, pi. 108, figs. 12-13.) 



BIDDUPLHIA CULCITELLA Mann 



(Mann, Diat., Alb. Voyages, p. 300, pi. 46, fig. 3. 



BIDDULPHIA CUSPIDATA (Janisch) Mann 



(Schmidt, Atlas, pi. 84, figs. 2-3.) 



The side (girdle) view of this species shows that the valve is flat, 

 not convex, and that the areolation extends through the border. It 

 can not be united with B.favus (Ehrenberg) Van Heurck, as is done 

 by Boyer (Bidd. Forms, p. 706). 



BIDDULPHIA CYCLOIDES, new species 



Plate 8, fig. 1 • 



Valve subcylindrical, with eight protruding processes, giving it an 

 octagonal outline ; surface slightly and evenly convex to the vertical 

 sides, covered with radiating rows of beading, the beads scattered in 

 the central part, becoming closer and more truly set in rows toward 

 the margin; the eight processes blunt, nearly sessile, protruding 

 beyond the margin; in side view the convex valve is seen to drop 

 vertically down to the rim, the depth of the valve being somewhat 

 less than one-third its diameter. 



Diameter, 0.057 to 0.099 mm.; Depth of latter, 0.031 mm. 



Although this diatom is not infrequent in Philippine dredgings no 

 complete frustule was found and therefore the girdle can not be 

 described. 



The only published species at all similar to this is Triceratium 



forresterii Pantocsek (Le Diat., vol. 1, pi. 1, fig. 2). But this lacks the 



Cerataulus like horns at the angles and is not evenly convex. There is 



a slight similarity to be seen in Cerataulus rotundus Tempere and 



Brim (Le Diat., vol. 1, pi. 5, fig. 3). 



Type— Cat. No. 43590, U.S.N.M. 



BIDDULPHIA DISCURSA, new species 



Plate 8, fig. 3 



Valve triangular, each side slightly distended until near the acute 

 apices; central portion of valve convexly elevated; horns narrow, 

 their basal portion dotted, not enlarged at the end; areolation a 

 hexagonal network, somewhat crowded and irregular in the middle of 

 the valve, becoming slightly larger toward the sides and regularly 

 arranged in rows not radial but parallel to the sides, the outside row 

 elongated toward the margin but not angled where its areolations 

 touch the margin ; this margin or rim is cross-marked with bars that 

 are enlarged into beads at their outer ends ; the secondary markings 



