24 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



I Valvi 



Valve thin . . . .4. 



solid . . . T. solidula Cl. 



j Frustule in zonal view elliptical T. antarctica Cl. 



\ — — — rectangular T. membranarea Cl. 



( Valve nearly flat ... . . . . T. longa Cl. 



\ — elevated . . . 6. 



I Wing close to the keel ... ... T. approximata Cl. 



\ — not — . . .... 7. 



(Central area indistinct or small T. Lepidoptera Greg. 

 distinct — . . . . T. maxima Gbbg. 



i Stria 



{ 



II. Plagiatropis Ppitzer, median line excentric; keels of the valves in contrary directions. 



•ise coarse and distant . . . T. Zehra Cl. 



close — . . . ... 2. 



n I Striae crossed by blank, longitudinal bands . . . . . T. seriata Cl. 



■ t ,— not — — — . . .... 3. 



„ I Valve not striate along the margin ... ... 4. 



'I — striate to the margin 5. 



. I Transverse striae about 15 in 0,oi mm. . . . T. japonica Cl. 



I — — — 19 — T. semistriata Grun. 



I Frustule constricted in the middle .6. 



not or slightly ... .... 9. 



„ J Wing or longitudinal band instinct ... . T. samoensis Grun. 



' I — — — distinct 7. 



„ f Valve broad . T. sumbavensis Cl. 



\ — narrow 8. 



g III. about 0,08 mm. . . . . T. gibberula Grun. 



I — 0,14 mm . T. chinensis Cl. 



Q I Valve narrow, almost linear . . . ... 10. 



' ' I — broader, lanceolate . . . 11. 



j„ ( L. 0,2 to 0,27 mm. ... T. elegans Greg. 



\ h. about 0,06 mm T. pusilla Greg. 



jj / L. 0,o« mm T. Van HeurcMi Grun. 



\L. 0,09 to 0,2 mm .' '. 12. , 



..„ (Longitudinal band, if present, not interrupted .... 13. 



' \ — — interrupted in the middle T. lata Cl. 



-„ j Longitudinal striae slightly finer than the transverse T. Kinkeriana Cl. 



1 — — much — — ' T. vitrea W. Sm. 



III. . Amphoropsis Grun., median line excentric; keels of the valves turned in the same 

 directions. 



I Keels without coarse ribs .... T. recta Greg. 



with — — T. concerta Lewis. 



. I Keels 



1. T. antarctica GtRUN. (1878). — Frustule membranaceous, elliptical in outline. L. 0,i 9 to 0,24; 

 B. 0,06 to 0,08 mm. Central area small, stauriform (the central nodule probably being a little 

 transversely dilated). Transverse and longitudinal strise 21 (16 to 18 Brun) in 0,oi mm., the me- 

 dian transverse strise more distant than the others. — Amphipr.? antarctica Gtrun. in Cl. M. D. 

 No. 125. Navicula Challengeri Grun. A. D. p. 64 (1880). Stauroneis glaciaHs Castrac. Voy. Challeng. 

 D., p. 25. PI. XXVII f. 11, 1886? Amphipr. fragilis Temp. u. Brun. D. fossiles du Japon, p. 14. 

 PI. IX f. 14 (1889). 



Marine, pelagic: Antarctic Ocean! Japan, fossil (Brun.). i 



2. T. membranacea Cl. (1873). Frustule membranaceous, rectangular, very slightly con- 

 stricted, with rounded angles. L. 0,25 to 0,35; B. 0,o7 to 0,125 mm. Central area indistinct. 

 Transverse strise 20 to 24, longitudinal 30 to 32 in 0,oi mm. — Amphiprora memhranacca Cl D 

 of the Sea of Java p. 12, PL II, f. 18. 



Marine, pelagic: Java! Sumbava (Kinker Coll.)! Cohm (Deby Coll.)! 



