MARINE DIATOMS OF THE PHILIPPINE ISLANDS 141 



Genus RHABDONEMA Kutzing 



RHABDONEMA ADRIATICUM Kutzing 



(Van Heurck, Synopsis, pi. 54, figs, 11-13; Schmidt, Atlas, pi. 217, figs. 17- 

 29.) 



RHABDONEMA ARCUATUM (Lyngbye) Kutzing 



(Van Heurck, Synopsis, pi. 54, figs. 14-16; Schmidt, Atlas, pi. 220, figs. 17- 

 22.) 



In Smith's British Diatoms, plate 38, his figures 305 and 305 + 

 are good illustrations of this species, but his figures 3056, a' and b' 

 are R. adriaticum Kutzing. 



RHABDONEMA MIRIFICUM W. Smith 



(Quart. Journ. Micro. Sci., 1859, pi. 9, fig. 11; Schmidt, Atlas, pi. 217, figs. 

 1-3.) 



Bailey and Harvey call this Hydlosira punctata in the Report of the 

 Wilkes Expedition, plate 9, figure 29. Grunow (Oest. Diat., p. 424) 

 creates the genus Climacosira for it. De Toni accepts this unneces- 

 sary assignment (Syl. Alg., p. 765). 



RHABDONEMA SUTUM, new species 



Plate 31, figs. 1-2 



Frustule in girdle view rectangular, slightly rounded at its four 

 corners and crossed by continuous lines which represent the series of 

 septa that become interpolated between the two ends or valves of the 

 frustule during its process of growth; the two sides of the frustule 

 bordered by bands about one-sixth its diameter, consisling of narrow, 

 straight, closely set costal bars, not enlarged or curved, between which 

 are single rows of small beads of blotches; these rows of beads con- 

 tinue across the frustule and join with those in the opposite band; 

 two median bands, of similar costal bars and beads, but in number only 

 one-half of those in the marginal bands and about twice as long, are sepa- 

 rated from each other and from the marginal bands by narrow spaces, 

 crossed only by the continuous beaded lines above mentioned; the 

 costae of the two median bands are bordered on either side by a row 

 of small beads and their ends are enlarged and slightly bent ; the two 

 valves and the interpolated septa are seen in face view to be very nar- 

 row, slightly dilated at the center and between the center and each 

 end ; a hardly perceptible median hyaline line bisects the rectangular 

 beading covering the surface of the valves, the ends being smooth; 

 the interpolated septa are each pierced by two openings, a small oval 

 one, corresponding to one of the dilations near to the end ; the other 

 and larger opening beginning at the middle dilation and running to 

 the small dilation near to the other end ; the parts of the septum not 

 pierced by openings is cross beaded like the valves and shows the 

 same faint median bisecting line, or pseudorhaphe. 



