J266_ 



Sch. viridulum (Colletonema viridulum Breb. in Ktz. Spee. p. 105. 

 Pritch. Inf. p. 926. Rabenh. Alg. sub No. 701 et puruni in N. 823.). 

 Sch. mediocre oblongo laneeolatum , apicibus obtusis , nodulo centrali 

 saepius quadrangulo plus minus dilatato , striis transversis subtilibus 

 46 — 50 in 0,001" subradiantibus lineam mediam triplicem vix attin- 

 gentibus. v. v. 



Long. l / 6 o— V» 1 " = 0,0014 — 0,0017", lat. 0,00045 — 0,0005". 



Hab. in aqua dulci Galliae (prope Falaise: De Brebisson), Ger- 

 maniae (prope Augustam Vindelicorum : Caflisch , Strehlen Silesiae : 

 Bleisch, Hilse) , Schweigfurtweiher prope Schussenried (Fr. Valet). 



Sch. lacustre Ag. (Syst. p. 10. Colletonema lacustre Ktz. Spec. 

 105. Pritch. Inf. p. 926.). Sch. naviculis ellipticis vel parallelogram- 

 mis, vel unica serie vel duplici annexis ; phycoma fiiiforme, simplex vel 

 subramosum , capillo tenuis , membrana involvente imperceptibili. — 

 Caespes semiuncialis , fuscoluteus. n. v. 



Hab. in lacu Miilaren Sueciae, ad pontem Traneberg rarissime. 



b. Frustula tum valvis tum linea media sigmatoidea, quasi 

 Pleurosigma in tubo gelatinoso (Endosigma Breb.). 



Scb. eximium Thwaites (in Ann. and Mag. 1848. T. XII. Col- 

 letonema eximium Ktz. Spec. 'Alg. p. 891. Sm. Diat II. p. 69. T. LVI. 

 F. 350. Pritch. Inf. p. 926. T. VIII. F. 43. Gloionema sigmoides 

 Ehrb. Abh. 1845. p. 78. Encyonema sigmoides Ktz. Spec. p. 62. 

 Endosigma eximium Breb. herb. et in litt.). Sch valvis lineari-sig- 

 matoideis utroque fine obtuso - rotundatis, nodulo centrali minimo, linea 

 media sigmoidea triplici, striis transversis parallelis rectis lineam mediam 

 attingentibus 56 in 0,001". v. s. 



Long. 1/35— ^'"—O^OO^S— 0,0034", lat. '/igt,— 7i72 y " = 0,00045 

 — 0,0005". 



Hab. in aquis submarinis et ad oras Angliae, Hiberniae , Galliae. 



Sch. subflexile (Colletonema subflexile Greg.). Rabenh. diff. linea 

 media subflexuoso-sigmatoidea, striis 48 — 50 in 0,001". v. s. 



Hab. in Scotia: Glenshira prope Inverary (Gregory). 



B. Phycoma gelatinosum ramosissimiim. (Schizonema 



Ag. et autor.). 



Species omnes marinae. 



a. Nodulus centralis transverse dilatatus. 



Sch. crucigerum Sm. (Diat. II. p. 74. T. LVI. F. 354. et T. LVII. 



F. 356. Rabenh. Alg. sub No. 1062. Stauroneis crucigera Heib. 



Consp. p. 88. N. 7.). Sch. phycomate filiformi ramosissimo caespitoso ; 



