142 Bacillariete, Naviculaceae, Navicula. 



sis radiantibus, delicatissimis, in valvse inedio 30 in 10 u.., irr api- 

 cibus raulto confertioribus. 



Hab. in lacu «Erlafsee» dicto prope «Mariazell» (Grunow). 



508. Navicula exilis Kuetz. Bacill. p. 95, t. 4, f. 6, Rabenh. Sirss. 508 

 Diat. p. 39, t. 6, f. 84, Fl. Eur. Alg. I, p. 198, Grun. in W. V. 1860, 



p. 553, t. 2, f. 30 a-d (excl. syn.), Schura. Preuss. Diat. 18G7, t. 2, 

 f. 31, 0'Meara Ir. Diat. p. 406, t. 34, f. 2, V. H. Syn. p. 101, t. 12, 

 f. 11-12! non Navicula falaisensis Grun. — Valvis lanceolatis, 

 angustis, 15-30-5, apicibus producto-capitellatis; nodulo centrali 

 parvo, oblongo; striis ut in Navicula seriante, circiter 30 in 10 u.. 

 Hab. in aquis dulcibus per Europam passira, imprimis in Ger- 

 mania (Kuetzing, Rabenhorst), Hibernia (O' Meara) et Galicia 

 (Gutwinski). 



509. Navicula microcephala (W. Sm.) Grun. Alg. Novara p. 19, V. H. S. 509 

 tab. 14, f. 29, Achanlhidium microcephalum W. Sm. Br. Diat. 



II, p. 31, t. 41, f. 380 vix Kuetz. Navicula exilissima Gruu mscr. 

 — Valvis elliptrco-lanceolatis, 10-12 u.. longis, apices versus con- 

 strictis; striis obscuris. 



Hab. in aqua dulci Gallise ad «Falaise» (?Brebisson) et Sco- 

 tia? (Dickie); in lacu (( Taupo » Nova? Zelandiae (Hochstetter). 



510. Navicula luxuriosa Grev. in Trans. Micr. Soc. 1862, p. 18, t. I, 510 

 f. 10-11, Grun. Alg. Novara p. 100. — Valvis ellipticis, 70-90 u.. 

 longis, subobtusis; striis transversis distincte punctatis, punctis in 

 lirreas longitudinales ad nodulum constrictas dispositis; margine li- 

 ueaque intramarginali punctis confertis donatis. 



Hab. in mari ad «Port Stephan, New South Wales» (Roberts); 

 in sabulosis ad «Auckland» Novae Zelandice (Frauenfeld). 



511. Navicula virginea Cleve Diatoms from the West Indian Archi- 51] 

 pelago p. 5, n. 33, t. I, f. 2. — Valvis subellipticis, medio saspe 

 constrictulis, apicibus productis; striis transversis subtilissimis, 

 parallelis, haud interruptis. 



Hab. ad insulas Virginum. — Navicukv Janischiancv Rabenlr. 

 arcte accedens. 



XVII. Formos.e V. H. Syu. p. 101. 



512. Navicula formosa Greg. in Trans. Micr. Journ. IV, 1856, p. 42, 512 

 t. V, f. 6, Sm. Sp. T. n. 274, A. Schm. Atlas t. 50, f. 8-14, V. 



H. Syn. p. 102, t. 11, f. 2. — Mediocris, valvis elliptico-linearibus 

 vel lineari-oblongis, circ. 140 s 30, polos versus sensim attenuatis, 

 apicibus conicis vel cuneatis, obtusis; rhaphe leniter flexuosa, zona 



