50 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. ' 



distant on the depressions (8 in 0,oi mm.) than towards the margin and the median line (18 in 

 0.0 1 mm.). — Diatomiste I p. 67 PL X f. 10. 



Marine: Macassar Straits! 



This form is perhaps to be considered as a distinct species. 



49. N. irapressa (Irfn. (1875). — V. elliptic-lanceolate. L. O.oc, to 0,o7.i; B. 0,034 to0,045 

 mm. Axial area indistinct, central area small. Strife 7 to ;i in O.oi mm. parallel in the middle, 

 slightly radiate at the ends. Pnncta coarse, 7 to 11 in O.oi mm. On both sides of the median 

 line are large lunate de])ressions. — A. S. Atl. VI f. 17, IS. 



Marine: Campeachy Bay! Sumbava (Kinker ("oil.)! 



50. N. sparsipunctata (thovb and Sturt (188G). — V. broadly elliptical, with rounded ends. 



L. 0,().-> to O.ocj; H. 0.0:1 to 0,04 mm. Central nodule very small. Terminal fissures indistinct. 

 Axial area narrow, lineai', unilateral, ("entral area indistinct. Strict loin 0,01 mm. parallel in the 

 middle, radiate at the ends. Puncta coarse, inequidistant, al)out (I in 0,oi mm. At some distance 

 from the margin is a narrow, not punctate, space. — Quek. M. CI. II (2) p. 323 PI. XVIII f. 1. 



Marine: Oamaru, New Zealand, fossil! 



This is a very remarkal)le form, not closely akin to any known species. The median line 

 and the central nodule are especially peculiar. 



51. N. inteiiineata (trove and Sturt (188()). — V. elliptic-lanceolate. L. (J,i; B. 0,o5 mm. 

 Axial ai'ea narrow, veiy slightly dilated ai'ound the central nodule. Terminal fissures indistinct. 

 Stria; 8 in 0,oi mm., radiate throughout. Puncta 8 in O.oi mm. forming irregularly undulating 

 rows. On both sides of the median line is a narrow, arcuate, lateral area, inside which the puncta 

 form more regular longitudinal rows. — J. Quek. M. C'l. II (2) p. 323 PI. XVIII f. 2. 



Marine: Oamaru, New Zealand, fossil! 



A very remarkable species, which shews some resemblance to IMploneis iiitkla. 



52. M. fraiululeiita A. S. (1881). — V. elliptical with rounded ends. L. 0,03 to 0,045; 

 B. 0,0 19 to 0,023 mm. Axial area indistinct. Central area small, not sharply defined. Stria; 14 

 (middle) to 18 (ends) in 0,oi mm. slightly radiate at the ends, composed of puncta, about 13 in 

 0,01 mm., disposed towards the median line in straight, somewhat distant, longitudinal rows. — 

 N. S. I). Ill p. 18 (without name). N. fraudulento A. S. Atl. LXX f. CO. X. restituta A. S. 

 accord, to (Trun. in CI. M. D. N:o 102 (1878). 



Marine: North Sea! Sebastopol! 



A small, very distinct species, not to be mistaken for any other. 



53. N. Nov* Giiineaeiisis Temp. (1891). - V. broad, biconstricted apiculate. L. 0,o4 toO,or. ; 

 B. 0,027 mm. ('entral nodule transversely dilated. Axial area narrow, linear. Central area trans- 

 versely dilated. Stria.' 11 in 0,oi mm., sti'ongly radiate at the ends, composed of coarse puncta, 

 about 7 in 0,oi mm. forming undulating longitudinal rows. — Diatomiste I p. 71, PI. XI f. 1. 



Brackish, water: Yule Island (New Guinea)! 



This is a very interesting form, not closely connected with any other. The median line 

 has somewhat arcuate components, which suggests that the valve is slightly genuHexed as in 

 Achnanthes. The coarse sti'ucture resembles that of Nar. Tuscula, but the direction of the termi- 

 nal rows of puncta is different and there is no appearance of a lineation across the puncta. The 

 dilated central nodule, as well as the strongly inclined striaj, remind one of the lower valve of 

 Achnanflic-^ danica and its allies, but the structure is much coarser and the valve strongly .silicious. 



54. N. Pi Cl. (1893) — V. rlioml)ic-lanceolate, with obtuse ends. L. O.os; B. 0,022 mm. Axial 

 area indistinct; centi'al area small. Terminal fissures in the same direction. Stria; 11 (middle) to 



