NAJAS ASPERA Sp. nov. 

 PI. II, figs. 15—17. 



Semina ambitu lanceolata, in apicem obtuse acuminatum curvata, rugosa, 

 foveolarum sexangularum ordinibus circiter 40 irregularibus ornata. 



Seed lanceolate, curved into the bluntly pointed apex, broadest about 1 /3 from 

 apex, then gradually narrowed towards the base ; testa rugose with about 40 irregular rows 

 of hexagonal pits, which become smaller less conspicuous and more elongate on the 

 prominent raphe, walls of pits very thick and forming wavy nodulose lines, due to the 

 hexagonal shape of the pit and the slight tuberculation where the cell* walls meet. 



Length 3.2 mm., breadth 0.9 mm. Brunssum. 



The seed of this rugose species resembles a small file, the rugosity being more 

 conspicuous than the striation. Owing to the irregularity of the rows it is impossible to 

 count them exactly, they appear to average about 40. This species does not seem to 

 be very near to any living form; at present it has only been found at Brunssum. 



NAJAS LANCEOLATA Sp. nov. 

 PI. II, figs. 18, 19. 



Semina ambitu elongato*lanceolata, superne in acumen obtusum curvata, 

 foveolarum haud altium elongatarum multiangularum ordinibus circiter 26 

 instructa. 



Seed elongate*lanceolate curved into a blunt point above, broadest about 2 / 5 from 

 apex, narrowed below and base rounded; testa thin smooth glossy, marked by about 

 26 rows of elongate polygonal shallow pits. 



Length 2.7 mm., breadth 0.6 mm. Reuver. 



The glossy surface marked with shallow pits and the elongate shape make this seed 

 very different from any known species. It has only been found at Reuver, where it is rare. 



NAJAS FUSIFORMIS Sp. nov. 

 PI. II, figs. 20, 21. 

 Semina fusiformia, parum curvata; testa crassa, haud translucida, asperula, 

 foveolis haud altis sexangulis irregularibus numerosis haud in ordines dispositis 



ORNATA. 



Seed fusiform slightly curved; testa thick and opaque somewhat rough, sculp* 

 ture numerous irregular shallow hexagonal pits, not arranged in definite lines, smaller 

 and elongate on the black scarcely^raised raphe. 



Length 2.8 mm., breadth 0.6 mm. Reuver. 



In size and shape this seed greatly resembles N. flexilis, though it is somewhat 

 larger than our recent specimens. It is however clearly distinguished by its thick rough 

 testa, covered by irregular pits which show little trace of linear arrangement. In this 

 respect it resembles N. marina; but it is quite different in other characters. 



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