26 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



6. T. approximat.a Cl. N. Sp. — V. narrow, lanceolate, with acute ends, very convex. L. 0,2 

 to 0,3; B. 0,034 mm. Central area indistinct. Wing unilateral, close to the median line. Trans- 

 verse striffi 19, longitudinal about 30 in 0,oi mm. — PI. Ill f. 20, 21. * 



Marine: Rembang Bay (Deby Coll.)! Macassar Straits (Grove Coll.)! Colon (Deby Coll.)! 



7. T. adriatica Cl. N. Sp. — Frustule narrow, linear, slightly constricted in tlie middle. 

 L. 0,18; B. '0,025 mm. Wings indistinct. V. narrow lanceolate. L. 0,2; B. 0,oi8 mm. Central area 

 small, transverse, narrowed towards the margin. Transverse striiie 15 to Ki, longitudinal 21 in 

 0,01 mm. — PI. Ill f. 22, 33. 



Marine: Adriatic! 



8. T. innxima CI-reg. (1857). — Frustule strongly constricted in the middle. L. 0,i 3 to 0, 1 7 ; 

 B. 0,04 to 0,07, at tlie constriction 0,022 mm. Wings very distinct, projecting beyond the ceiiti'al 

 nodule. V. lanceolate, acute. L. 0,22 to 0,24; B. 0,032 to 0,o33 mm. Wing unilateral. Centi-al 

 area distinct, nai^row, transversely lanceolate. Transverse striae 15, longitudinal 21 in 0,01 mm., a 

 little more distant outside the wing. — Amphiprora maxima Greg. D. of Clyde p. 507, PI. XII 

 f. (U. V. H. Syn. p. 120 PL XXII f. 4, 5. Grun. A. D. p. 65. 



Marine: North Sea! Mediterranean Sea! Adriatic! Java! Macassar Straits (Grove Coll.)! 



Var. suhalata Cl. — L. 0,i.'i mm. Wing not projecting beyond the central nodule. Trans- 

 verse striitt 19 in 0,oi mm., more distinct in the middle, punctate; puncta forming undulating, 

 longitudinal rows, about 16 in 0,oi mm. 



Marine: Macassar Straits (Grove Coll.)! 



Var.? decussata Cl. — V. in L. 0, le; B. 0,o24 mm. Transverse striaj 15 in 0,oi mm., punctate; 

 puncta forming fine decussating lines, about 19 in 0,01 mm. — PI. Ill f. 24, 25. 



Marine: Seyshelles (Van Heurck Coll.)! 



Var. duhia Cl. a. Grun. (1880). — L. 0,072 to 0,09; B. 0,012 to 0,013 mm. Central area 

 rounded. Transverse strite 17 to 18 in 0,oi mm. — Amphipr. maxima var. duhia A. I), p. 65. 

 PL V f. 89. 



Marine: Finmark! 



It seems to be generally considered that there are wings on both sides of the median line, 

 but so far as I liave seen, on examining a number of specimens, there is a wing only on one of the 

 sides. The wings of one frustule are diagonal. The following insufficiently described and figured 

 species seem to be akin to T. maxima: Amphiprora ohlonga Grev. (T. M. S. XI p. 20, PL I f. 15, 

 1863), Amphipr. eximia Grev. (Edinb. N. Ph. J. XVIII p. 36 f. 13, 1863), Amphipr. Wcndtii Witt 

 (J. Mus. Godeff'r. H. I p. 69 PL VIII f. 3, 1873). 



9. T. sumbavensis Cl. N. Sp. — V. lanceolate, gibbous in the middle. L. 0,1.'-.; B. 0,o3 mm. 

 ('entral area unilateral, quadrate. AVing unilateral, very distinct. Transverse striai 19 in 0,oi mm. 

 Longitudinal stride very fine. 



Marine: Sumbava (Kinker Coll.)! 



This form is evidently nearl}^ akin to T. maxima. 



10. T. gibb(^nila (tiuun. (1882). — Frustule rectangular, with rounded angles, constricted in 

 the middle. L. 0,07 to 0,oy; B. 0,017 mm. Wing slightly projecting outside the central nodule. 

 V. narrow, lanceolate, with subcapitate ends, iufequilatei'al, the broadest side having a gibbosity 

 in the middle. B. 0,02 mm. Stritie 16 in 0,oi mm. finely punctate. — Flaylotropis qihherula Grun. 

 in Cl. M. D. N:o 309. V. H. Syn. PL XXII bis f. 12, 13. 



Marine: Fii'th of Tay! (^hina (Deby Coll.)! 



n. T. piisilla Greg. (1H57). — Frustule rectanguhu-, with rounded angles, scarcely constricted 

 in the niiildlc. L. 0,055; B. 0,oi2 mm. V. narrow, lanceolate, unilaterally gibbous. Central area 

 iii(listin(;t. Stria; 15 in 0,oi mm. — Ani/ihipr. pnsiJla ({reg. D. of Clyde |). 504 PL XII f. 56. 



Marine: North Sea (Coasts of Scotland! Belgium!) 



