1*2 Bacillarieae, Navieulaceoe, Navioula. 



minuta ; valvis late ovato-lanceolatis, obtusis, 20-21 -9,5, polis ob- 

 solete productis, rotundatis, nodulo centrali parvo; striis transver- 

 sis tenuibus, 20-22 in 10 u., radiantibus. Ad fragmentum glaciei 

 maris arctici. 



632. Navicula leptorhynchus Ehr. Verbr. p. 130, Rabenh. Siiss. Diat. 632 

 p. 40, Kuetz. Bacill. pag. 95. — Levissima, parva, valvis lineari- 

 lanceolatis, apicibus longe rostratis, rectis, subacutis. 



Hab. in aquis dulcibus in Mexico (Ehrenberg). 



633. Navicula cyclophora Castrac. Diat. Challenger p. 31, t. 28, f. 18, G33 

 Notarisia 1889, p. 687. — E minimis, valvis elliptico-subinflatis, 



12 5 10 (ex icone), apicibus obtuso-rotundatis; striis radiantibus; 

 cyclo laterali ad nodulum centralem praesente. 



Hab. in mari Antarctico inter ins. aKerguelen» et a Heard » 

 (Exped. Challenger). — Cfr. Castr. Ciclof. 1889. 



Huc accedere videntur. 



634. Navicula Fistula A. Schm. Nordseef. p. 90, t. II, f. 29. 634 

 Hab. ad aHvidingsoe» (A. Schmidt). 



635. Navicula minuscula Grun. in V. H. Syn. t. 14, f. 3. 635 



636. Navicula muralis Grun. in V. H. Syn. t. 14, f. 26-28. 636 



XXIV. Pseudopleurosigma. Grun. in Cl. et Gr. Arct. Diat. p. 4G. 



637. Navicula Rotaeana (Rabenh.) Grun. in V. H. Syn. t. 14, f. 17, G37 

 Stauroneiz Rolaeana Rabenh. in Hedwigia I, p. 103, t. 13, f. 7, 

 Alg. n. 505, Fl. Eur. Algar. I, p. 249, Grun. in Wien. Verhandl. 

 1860, p. 565, t. 4, f. 14, Siauroneis minuta Kuetz. Species p. 89, 

 Rabenh. Fl. Eur. Algar. I, p. 249? — Valvis ex ovato late lan- 

 ceolatis, 12-24 u. longis, apicibus rotundatis, obtusulis, area trans- 

 versa levi valvarum marginem utrinque attingente vel subattin- 

 gente; striis transversis delicatissimis, 18-23 in 10 u. 



Hab. in molis aquariis prope aBergamo» Italise (L. Rota), in 

 fossis rivulisque ad « Menton » Galliae (Boettcher), Thuringias, 

 Helvetise, Saxoniae, Lusatiae superioris, Nassovue, Holsatise (Raben- 

 horst, Kuetzing), in Austria inferiori (Grunow); in aMajskowa» 

 Galicias (Gutwinski). 



638. Navicula 0'-Mearii Grun. in Cl. et Gr. Arct. Diat. p. 61, Cl. Diat. 638 

 Vega p. 496 (f. typica). — Valvis lanceolatis, 59-68^9-11,5, re- 

 ctis, apicibus subacutis, rhaphe recta, nodulo centrali minutissimo; 

 striis transversis leniter radiantibus v. subparallelis, 17 in 10 a.; 

 striis longitudinalibus rectis, 20 in 10 a. 



