MARINE DIATOMS OF THE PHILIPPINE ISLANDS 153 



SURIRELLA CONTINUATA, new species 



Plate 33, fig. 3 



Valve a broad oval, the outer rim narrow, stout, finely crossbarred 

 and beset with a row of minute processes near the outer edge; no 

 alae; the costae or ribs begin at the rim in a row of lozenge-shaped 

 enlargements elevated above the rim and draw to a point at their 

 outer angle; from there inward they are very narrow, without 

 beading, but showing two undulations, a strong sharp one a little 

 less than half the distance to the middle of the valve, thereby pro- 

 ducing the effect of an inner oval parallel with the outer one, and a 

 second less pronounced undulation appearing as a still smaller oval 

 within the other; the costae extend clear to the median line, those 

 from one side generally, but not invariably, continous with those 

 from the other side; polar areas on the margin evident. 



Long diameter, 0.162; short diameter, 0.097 mm. 



The nearest known species to this is S. tridens A. Schmidt (Atlas, 

 pi. 206, fig. 177) from the not distant Sumbawa. 



Type.— Cat. No. 43684, U.S.N.M. 



SURIRELLA CUNEATA A. Schmidt 



(Schmidt, Atlas, pi. 4, figs. 1-2.) 



Possibly a variety of S. fastuosa Ehrenberg. 



SURIRELLA CUNEATELLA, new species 



Plate 33, fig. 4 



Valve narrow ovate, small but robust; rim narrow but heavy, 

 strongly and closely crossbarred; ribs or costae beginning at the 

 margin in very large pear-shaped plates elevated above the rim, 

 striped lengthwise with strong moniliform lines and bearing one to 

 three minute teeth on the broad outer end; short and very thin 

 costa connect the small internal ends of the plates with a narrow 

 median area, which is bounded by a closely set row of transverse 

 lines; polar areas of the long diameter obscure. 



Long diameter, 0.065-0.071 ; short diameter, 0.034-0.035 mm. 



This belongs to the loosely defined S. fastuosa Ehrenberg group. 

 It is rather abundant in Philippine Islands material, is uniformly 

 minute but robust and heavy and strongly ovate. In shape it resem- 

 bles Schmidt's S. cuneata (Schmidt, iitlas, pi. 4, fig. 2), which is, how- 

 ever, much larger, relatively less massive, and has a different border. 

 It is perhaps nearest to the unnamed figure in Schmidt's Atlas (pi. 4, 

 fig. 23) from the relatively near-by Surabaya, Java, 



Type.— Cat. No. 43685^, U.S.N.M. 



