MARINE DIATOMS OF THE PHILIPPINE ISLANDS 151 



Genus SURIRELLA Turpin 



SURIRELLA BERTILLONH, new species 



Plate 33, fig. 2 



Valve reniform by lateral expansion, not by an incurving of one 

 side, the two polar ends being joined by the narrower axis, one end 

 at the middle of the convex margin the other in the sinus of the 

 concave margin; border massive, its outer edge strongly crossbarred; 

 within this is a row of wedge-shaped elevations, touching each other 

 at the outer wide ends, from the inner and pointed ends of which 

 proceed single or double curved rows of beads to the pear-shaped 

 central area of the valve; this area extends across the middle of the 

 valve, its narrower end being at the polar point or center on the con- 

 vex side and its wider end at the other polar point or center on the 

 concave side of the valve; it is bounded by a fringe of closely set, 

 short, radiating lines, like the cilia around certain Infusoria, and 

 its surface is marked with dim scattered beads or blotches. 



Longer (lateral) diameter, 0.087-0.097; shorter (polar) diameter, 

 0.046-0.050 mm. 



Like Surirella reniformis Grunow and Coscinodiscus reniformis 

 Castracane ( = Stoschia admirabilis Janisch) , this kidney-shaped dia- 

 tom at first seems to be only an odd monstrosity. But on fuller ac- 

 quaintance it displays a uniformity of shape that entitles it to specific 

 rank. C. reniformis Castracane proves to be abundant in many widely 

 separated localities and is everywhere true to its curious shape. So 

 also is S. reniformis Grunow. Both are abundant in the Philippine 

 Islands and all the specimens keep close to the type form. This spe- 

 cies, S. bertillonii, was found in three quite dissimilar dredgings and 

 exhibits practically no variation, either in outline or in plan of 

 sculpture. 



The specific name here given refers to the very curious resem- 

 blance of its markings to the thumb prints used in the Bertillon 

 system of criminology. 



Type.— Cat. No. 43681, U.S.N.M. 



SURIRELLA CASTRACANEI De Toni 



(De Toni, Syl. Alg., p. 588. See Castracane, Challenger Exp., p. 61, pi. 10, 

 fig. 6.) 



Castracane's name, S. multicostata, being preempted by Leuduger- 

 Fortmorel (Diat., Ceyl., pi. 3, fig. 40), De Toni renames it as above. 

 Schmidt subsequently named the same diatom S. sumbawana (Schmidt, 

 Atlas, pi. 205, figs. 1-2). 



SURIRELLA CEYLANENSIS Leuduger-Fortmorel 



(Leuduger-Fortmorel, Diat., Ceyl., pi. 3, fig. 38; Schmidt, Atlas, pi. 309, figs. 

 4-5.) 



The Philippine Islands form is the trivial variation from type that 

 Hustedt calls var. oblongistriata in the above reference in Schmidt's 

 Atlas. 



