210 



dcnticulatis achrois, in apicc trifuvcatis; semiccllulis cllipticis vel latcrc 

 vcntrali intiatis subtrigonis , undique vcrruculoso -aspcris, a vcrtice tri- 

 radiatis, vadiis elongatis asperis , in apice trifurcatis , laterum medio 

 prominentiis geminis, modo subulatis modo bifurcatis. v. v. 



Long. circitcr 1 /m'" = 0,00165", latit. c. radiis ad V'32'" = 

 0,0027". 



b. diplacanthum (Staurastr. diplacanthum De Ntris Element. p. 49. 

 X. 87. T. IV. F. 38.), semicellulis et a fronte et a vcrtice radiis minus 

 productis, prominentiis marginalibus singulis elevatis. 



Hab. in fossis, fodinis turfosis totius Europae, passim. 



St. oxyacanthum Archer (Micr. Journ. 1860. T. VTT. F. 1 et 2. 

 in Pritch. Inf. p. 742. Rabenh. Krypt. Flor. v. Sachs. p. 193.). St. 

 mediocre, granulis in lineas transversas dispositis asperum ; semicellulis 

 oblongo - fusiformibus , conniventibus, latere ventrali saepe inflatis, dorso 

 leviter convexo prominentiis 5 — 6 aut acute subulatis aut truncatis in- 

 structis, angulis longe productis, incurvis , 3 — 4-furcatis, achrois, a 

 vertice triradiatis, radiis elongatis spinulosis apice trifidis. v. v. 



Diam. lat. c. processibus »/52 — V = 0,0017 — 0,00157", 

 longit. Ves'" = 0,00129". 



Hab. in stagnis prope Dublin in Hibernia ; in Saxonia primus reperit 

 beat. Bulnheim. 



St. furcigerum Brcb. (in Menegh. Syn. in Linn. 1840. p. 226. 

 M*. 3. Liste p. 136. N. 1. Rabenh. Krypt. Flor. v. Sachs. p. 194. 

 Oleve 1. c. N". 22. Hilse in Ber. der schles. Ges. 1865. p. 123. 

 Archer in Pritch. Inf. p. 743. Reinsch. Algenfior. p. 170. Didy- 

 mocladon furcigerus Ralfs Brit. Desmid. p. 144. T. XXXIII. F. 12. 

 Rabenh. Alg. N. 569, sub No. 1568, 1703. Didymocladon sexangularis 

 Bulnh. Hedwigia II. T. IX. F. 1. a— d. Rabenh. Alg. sub No. 1568. 

 Phycastrum furcigerum Ktz. Phycol. gcrm. p. 138. N. 8. Asteroxanthium 

 furcigerum Ktz. Spec. Alg. p. 183. N. 2.). St. validum, submagnum, 

 circiter tam longum quam latum, laeve vel subtiliter granulatum, plerum- 

 que profundissime constrictum, sinu angusto lineari ; semicellulis oblongo- 

 eliipticis, plus minus tumidis, angulis in processus bifurcum aut rcctum 

 aut divergentem longe productis, dorso processibus similibus 2, 3, 4 in- 

 structis, omnibus processibus achrois granulato-dentatis, granulis in series 

 transversas ordinatis, a vertice 3-, 4-, 6-, 7-, 8-, 9 -angularibus vel 

 radiatis , angulis plus minus tumidis , in processus crassum achroum 

 asperum in apice fissum productis. v. v. 



