6 Bacillarieae, Naviculaceae, Navicula. 



D) Genus raihi parum cognitum vel dubiurn. 



Porostauros Ehr. — Genus Naviculaceis adscriptum, mihi adhuc plane 

 ignotum. 



E) Genera delenda. 



Perizonium C. et J. — Statum sporangialem Navicuhie sistens. 

 Craticula Grun. — Statum abnormen sistens (incl. Sticlodesmis Grun.). 



II. Stratus interior costarum praesens (Mastogloiacece auct. *j). 



Mastogloia Thw. — Frustula solitaria vel aggregata, muco gelatinoso (an 



semper?) coalita [incl. Stigmaphora Wall.]. 

 ? Pleurosiphonia Ehr. — Valva- canalibus margine instructae (Vix a Masto- 



gloia differre videtur). 

 [? Diadesmis Kuetz. sec. Lagerst. Diat. Spetsb. pag. 33 est, saltem pro parte, 



Navicuhe adscr.]. 



NAVICULA Bory ') [1826?] Dict. class. XI, p. 472, Cfr. Leman Dict. 

 V, 34, 1825, p. 318 ampl. (Etym. navis ob valvarum formam sae- 

 pius lanceolatam), Kuetz. Bacill. 1844, p. 91, Sp. 1849, pag. 69, 

 Rabenh. Fl. Eur. Algar. I, p. 169, Grun. in Wien. Verhandl. 1860, 

 p. 513, Kirchn. Alg. Schles. p. 177, Van Heurck Syn. p. 71, Truan 

 Diat. Astur. p. 34 et seq, Donk. Brit. Diat. 1870, p. 2, Brun Diat. 

 AIp. p. 63, Pinnularia Ehrenb. [1840] in Ber. Akad. Berl. 1840, 

 p. 213, Brun Diat. Alp. p. 81, Kirchn. Alg. Schles. p. 173, non 

 Pinnularia Lindl. et Hutt. 1831 [quse genus plantarum fossilium 

 sistit], Diploneis Ehrenb. [1844] in Ber. Akad. Berl. 1844, p. 84, 

 Stauroplera Ehrenb. [1843] Amer. pag. 134, Kirchn. [1878] Alg. 

 Schles. p. 177, Anomoeoneis et Neidium Pfitz. [1871] Unters. in 

 Hanstein Bot. Abh. I, Heft 2 pag. 39, 77, Bacillaruv, Cymbelltv, 

 Pleurosigmatis, Frusiulirv, Slauroneidis, Rhoiconeidis species 

 auct. nonnull. — Frustula libera, rarissime subseriato-coalescentia; 



*) Mastogloiam in Naviculaceis potius quam Cocconeidaceis disposui, ob 

 praesentiam noduli centralis genuini rhaphesque in utraque valva. 



1) In genere hoc vastissimo pertractando, multa mihi dubia adfuerunt, an 

 idem in plura genera distinguerem (ex. gr. Pinnulariam, Diploneidem, Stau- 

 ropteram, Neidium, Anomceoneidem etc.) utrum in plures sectiones, ad nor- 

 mam clarorum Grunow, Van Heurck, Cleve etc. species ordinarem. 



Veniam ergo dent mihi diatomologi: nam monographis tantum datum erit 

 hoc genus chaoticum, speciminibus authenticis iconibusque comparatis, extri- 

 care! In calcem generia vel singuhe sectionis diagnoses vel nomina specie- 

 rum mihi incertarum tam cel. Ehrenberg quam Kuetzing aliorumve tran- 

 scripsi, nolens in mea Sylloge formas ullas, etsi dubias, silentio prsetermittere. 



