394 RIIODYMKNIEJE. Plocam'ium. 



fixa, dein supra funduiu cxpansa, basalis, sursuin sparsis fills cum 

 pericarpio conjuncta, fila plurima sporigena emiltens. Fila articulata, 

 elavato-moniliformia, in fascicules plurcs srcpo collccta, a placenta 

 egredientia; fasciculus unus vcl alter sterilis (? ant juvonilis ?) or- 

 gana sistit, qua> Kiitzing paraspertnatia nuncuput; ferlilis fasciculi 

 gemmidia angulata, in articulis lilorum nata plurima. Sphoorosporrc 

 in cellulis strati interioris nalao, oblongae, in sphorophyllu longitu- 

 dinaliter subseriata;; series nunc unica, mine duo collaterales. Spo- 

 rophylla transvorsim secta terctia conspiciuntur, sphserosporis ge- 

 jninis transversaliter collateralil)iis in sporopbyllis unica longitudinal! 

 serie donatis. 



Genus PJocamii, a Lamouroux institulum, Plocamii species non- 

 nullas, Bostrychias. Bonnemaisonias, Ctcnodos, Ptilotas etc. compre- 

 licndebat. Male constructuin genus in speciebus Alga rum C. Agardhi 

 dissolvobatur, et Plocamii species alife inter Delesserias introductiic, alia 

 novum genus Tbamnophorfe, cujus tantum sporopliylla cognita orant, 

 constituererit. Lyngbye nomine Plocamii novum genus PI. coccineo 

 linxit; Greville genus Lyngbyeanum adoptavit, a Thamnopbora species 

 qiiasdam, cum dubio introductas, expulsit, atfjue Plocamium Tham- 

 nophone proximum posuit. Ipse dein utriusf|iie generis affinilatem 

 agnoscens, cbaractcrem vegetationis, ulroque generi diagnosticum, 

 indicavi. Kiitzing in Phycologia novum genus Thamnocarpi intro- 

 duxit. Harvey demum Thamnoplioras Thamnocarpum ct Plocamium 

 in unuin genus conjunxit. Sonder lioc natura; injtiria factura dc- 

 claravit, difTercntiain structurnc inter Plocamia et Tliamnoporas in- 

 dicans. Kiitxing in recentissimo opere plurimas Thamnophorae species 

 Plocamio rolulit, Tliamnophoram Th. corallorhiznc restrinxit et Tham- 

 nocarpum suum nova s|iecie atixit. 



Pcrquirenti milii, quamaDi opinio inter divergentcs verior, qiuie- 

 nam naUirre magis consentanea, adparuit nulluin a structura csse 

 liauriendum distinctionis cbaracterem. Tliamnophoram, Thamno- 

 carpum et Plocamium, qualia a Kiit/ingio constructa, juventute eco- 

 stata. senilia s;ppe costata et triplex stratum I'ero offerentia. Cysto- 

 carpia in Plocamio frondi innafa, solitaria et sparsa, in Thamnophora 

 pedicellata et fasciculata vidi; sed nee huic characteri irisistere ausus 

 sum, quiim in Thamnocarpo cornuto, qui <juoad vegetationis cha- 

 racterem Thamnophoras, quoad cystocarpia Plocamio convenit, fruclus 

 sessiles obscrvarem. Sporopliylla in Plocamiis plurimis transfor- 



