198 Bacillarieae, Naviculaceae, Rhoiconeis. 



linearibus vel subquadratis. 46-82 s 22-45, valvis lineari-lanceola- 

 tis, 10-12,5 u. latis, obtusiusculis, nodulo centrali magno oblongo; 

 striis transversis subradiantibus, 17-18 in 10 u., rnembrana con- 

 nectivali seriebus- duabus v. quatuor striarum brevissimarum, circ* 

 14 in 10 u.. ornata. 



Hab. inter Algas varias in Oceano pacifico boreali (Garke). 



3. Rhoiconeis Bolleana Grun. in Wien. Verhandl. XTII, p. 147, t. 13, 848 

 f. 11. — Frustulis e facie connectivali visis late linearibus, 40- 



48 s 17-22, genuflexis, valvis lineari-lanceolatis, 10 u. latis, obtu- 

 siusculis; striis transversis subradiantibus, distinctissimis, in valva 

 inferiori T 1 ^-^, ir« valva superiori O^-IO in 10 u. 



Hab. aliis algis insidens in Oceano pacifico boreali (Grunow) ; 

 ad oras Spetsbergise, Groenlandise, Finmarchise, in mari Kariano 

 (Cleve); ad Caput uHorn)) Americee australis (P. Petit) ; intra 

 Salpam prope portum Messanense Siciliae (Castracane). — Var.? 

 Sibirica Grun. in Cl. et Moll. Diat. n. 302, Cl. Diat. Vega p. 460, 

 t. 37, fig. 38: frustulis e facie connectivali visis minus arcuatis ; 

 striis subparallelis, 10 in 10 [j.., transverse lineolatis. Ad Caput 

 uWankareina». — Var. asymmetrica Cleve Diat. Vega pag. 460, 

 t 37, f. 39; valvis 45-10; striis asymmetricis, 11 in 10 u. Cum 

 varietate praecedente. 



4. Rhoiconeis superba Cleve Diat. Vega p. 468, t. 36, f. 23-24 (sub 849 

 Navicula). — Valvis rhombicis, 60 s 20, arcuatis (vel subinde re- 

 ctis); valvis convexis et concavis, plus minus diversis; striis sub- 

 parallelis, transverse lineatis, in valva convexa medio 9, apices ver- 

 sus 10 fn 10 u., rhaphen attingentibus, in valva concava 8-10 in 



10 «.., in uno latere rhaphen non attingentibus, in altero rhaphen 

 attingentibus sed area lineari interruptis. 



Hab. ad Caput « Wankarema » maris arctici. — Var. elliptica 

 Cleve I. c. p. 469, t. 36, f. 24: valvis ellipticis, 65 s 20; striis pa- 

 rallelis, 10 in 10 fx. Cum typo. Valva hujus varietatis concava vix 

 a Navicula (Rhoic. ?) incudiformi Cleve differt. 



5. Rhoiconeis ? incudiformis (Cleve), Navicula incudiformis Cleve 850 

 Diat. Vega p. 467, t. 36, f. 26, 30, Navicula Incus var. abbre- 

 viata Grun. in Cl. et Gr. Arct. Diat. p. 39, t. 2, f. 43. — Valvis 

 50-95 u. 1., subinde arcuatis; striis transversis 8 in 10 u.., in uno 

 latere valvae magis quam altero rhaphi approximatis et interruptis. 



Hab. ad Caput « Wankarema » (Exped. Vega). — Rhoiconeidi 

 swperbaz Cleve proxima. 



6. Rhoiconeis obtusa Cleve in Cl et Moll. Diat. n. 315-318, Diat. 851 



