Bacillariere,. Nitzschiaceae, Nitzschia. 495 



4. Bacillaria prselonga (Cleve) De-Toni, Nitzschia prcelonga Cleve in 1994 

 Cl et Gr. Arct. Diat. 1880, nag. 85, Cleve On Some new or little 

 known Diatoms 1881, p. 16, t. IV, f. 48. - Valvis anguste li. 

 nearibus, leniter arcuatis, 2^0 « 9, apicibus productis, carina sub- 

 centrali; punctis carinalibus 4-5 in 10 u..; striis transversis vah- 

 diusculis, 16 in 10 p.. 



Hab. ad insulas Balearicas, haud raro (F. Soederlund). — Fru- 

 stula valde elongata, gracillima, leniter arcuata, linearia, apicibus 

 oblique cuneatis. 



NITZSCHIA Hassall [1845] Br. Freshw. Alg. (nom. Gyrosigma a W. 



Smith in Pleurosigma rautatum) em. Grun. [1880] in Cl. et Gr. 



Arct. Diat. p. 67 (Etym. a cl. C. L. Nitzsch, de Infusoriorum et 



Bacillariearum historia optime raeritus), V. H. Syn. p. 169, Trij- 



blionella W. Sra. [1853] Br. Diat. I, p. 35, Grunowia Rabenh. 



[1864] FI. Eur. Algar. I, p. 146, Priichardia Rabenh. [1864] Fl. 



Eur. Algar. I, p. 162, Nitzschiella Rabenh. [1864] Fl. Eur. Algar. 



I, p. 163, Sigmatella Kuetz. [1833] in Alg. Dec. I, n. 2 et [1849] 



Sp. p. 18, Frustulicu, Ctjmbellce, Naviculcv, SjnedrcB, BacillaricB, 



Ceratoneideis sp. auct. nonnull. — Valv£e carina instructse, punctis 



carinalibus brevibus vel in costas breves prolongatis, rarius totara 



valvara percurrentibus. Carinre utriusque valvfe diagonaliter op- 



posit^. Frustula libera, raro tubis {Schizonematis raore) inclusa 



vel seriata. — Ph^ophora singula e laraina in parte media frustuli 



partim vel ex toto interrupta efFormata (Cfr. op. 0. Mueller). 



Obs. Noraen Sigmatella a cl. Kuetzing jam anno 1833 datura 



videretur, prioritatis lege, aptius sumendum. 



Sectio I. Tryblionella (W. Sm. ex parte) Grun. [in Cl. et Gr. Arct. Diat. 

 p. 67]: Carina valde excentrica. Valvas pleruraque undulato-plicatfe. Pun- 

 cta curinalia indistincta, plerumque eodem numero ac stri» transversse. 



1. Nitzschia navicularis (Breb.) Grun. Arct. Diat. p. 67, V. H. Syn. 1995 

 p. 171, t. 57, f. 1, T. n. 371, Dannf. Diat. Balt. p. 35, Trijblio- 

 nella namcularis (Breb.) Rabenh. FI. Eur. Algar. I, p. 147, Su- 

 rirella navicularis Breb. in Kuetz. Spec. Alg. p. 36, Tryblionel- 

 la marginata W. Sm. Br. Diat. I, pag. 35, tab. X. f. 76. — Ob- 

 longa, utroque iBne dilatata, truncata, membrana connectiva lata 

 longitudinaliter striata; valvis ovato-lanceolatis, 35-60 a. longis, 

 apicibus acutatis, striis transversis validis, perviis, 7 in 10 u., ad 

 raarginem in seriem duplicera punctorum desinentibus. 



Uab. in aquis submarinis nec non ad oras Anglise ad «HuIU 



