160 
55. R. alata, var. gracillima (Cl.) Van Heurck. 
IX a 1 4 /i i (rr), 15 /n (rr) — Xa 16 /u (rr) — X 2 Vs (c) 
- Xb 18 /n (rr) — Xc Vs (r). 
56. Æ. alata, var. indica (H. Perag.) Ostf. ras.; R. indica 
H. Peragallo, Monographie du genre Rhizosolenia, 1892, p. 116, ' 
PI. 5, f. 16; R. alata var. corpulenta Cleve, Phytoplankton, p. 24, 
PI. 2 f. 11. 
Rhizosolenia hyalina Ostf. 
C 400 /!, 7 °°/l.) 
Der er næppe nogen Tvivl om, 
at Peragallo’s R. indica er identisk 
med Cleve’s var. corpulenta og man 
maa følgelig benytte Peragallo’s 
Navn som det ældste. Maaske bør 
ogsaa R. quadrijuncta H. Peragallo, 
ibid., f. 17 føres hertil. 
VII a 9 /u (+) — VIII 18 /n (rr) 
- Xb 2 /s (rr) -Xc 3 / 5 (+). 
57. R. cylindrus Cleve, Phy to¬ 
plankton, p. 22, PI. 2, f. 12. 
IX Vs (rr) — X b 18 /u (rr) — 
X 27 / 2 (rr). 
58. R. hyalina Ostf., n. sp. 
Frustule very slightly silicious 
(length 280—340 p , width 28 — 
32 p); structure hardly visible, 
squamate (4 — o squamæ at the same 
height) ; spine (32—40 p long) very 
thin, slowly incrassated at the base; 
valve in a front view with a cha- 
racteristic undulation of the contour 
and with a fis sur e ; in whicli the 
spine of the neighbour-cell is fastened. 
En ejendommelig fin Art, hvis 
Strukturforhold er meget vanskelige 
