MARINE DIATOMS OF THE PHILIPPINE ISLANDS 43 



BIDDULPHIA PAPILLATA (Grove and Sturt) Mann 



(Grove and Sturt, Oamaru Diat., p. 14, pi. 6, fig. 14.) 



BIDDULPHIA PENTACRINUS (Ehrenberg) Boyer 



(Schmidt, Atlas, pi. 98, figs. 7-13.) 



BIDDULPHIA PETITIANA (Leaduger-Fortmorel) ? Mann 



Plate 10, figs. 4, 5 



I figure this unique and rare diatom because, although I can not- 

 separate it from Triceratium petitianum as figured and described by 

 Leuduger-Fortmorel (Diat. Cot. Occ. Africa, p. 28, pi. 5, fig. 12) and 

 probably including the unnamed figure in Schmidt's Atlas on plate 

 94, figure 10, it differs very greatly from it in its markings. The 

 original is covered with coarse, irregularly placed beads or blotches, 

 with no reticulations. There can be no question of error in this, 

 because the diatom is carefully described and twice illustrated and 

 several specimens were found, as is indicated by the measurements 

 given. In contrast to this, the valves of all my specimens are covered 

 with a coarse strong reticulation, except on the ends of the two proc- 

 esses, and within the reticulum are accurately arranged rows of fine 

 perfect beading, radiating from the center of the valve and also cover- 

 ing the unreticulated ends of the two processes. In the center is a 

 single blunt curved spine. The girdle is covered with closely set 

 regular rows of beads running vertically, that is, across the girdle, 

 the beads being of the same size as those on the valve. 



Length of valve, 0.056-0.059; width, 0.037-0.039; height of fr us tule, 

 0.085-0.079 mm. Length of valve of Leuduger-Fortmorel specimens, 

 "4-7 c.&.mr 



Type.— Cut. No. 43596, U.S.N.M. 



BIDDULPHIA PETITII (Leuduger-Fortmorel) Mann 



Plate 8, fig. 4 



(Leuduger-Fortmorel, Diat. Malaisie, p. 39, pi. 6, fig. 3.) 



Cerataulus turgidus Ehrenberg has been made the repository for 

 several allied forms having in common massive, oval and convex 

 valves, with two heavy blunt horns capped with round or oval hya- 

 line ends, analogous to the ocelli of certain species of Auliscus, and 

 generally set one near to each end of the long axis of the valve but 

 a little to one side of it. To a few forms distinctive names have been 

 given, but several species still appear under the old Ehrenberg name. 

 The best collections of figures of diatoms of this group are to be found 

 in Schmidt's Atlas, plates 115 and 116, and in A. Forti's Contributions 

 to Diatoms, 1910, plates 1 and 2. 



