586 Eu-Floridez, Plocamiez, Plocamium. 
PLOCAMIUM Lamour. [1813] in Ann. Mus. XX, pag. 197, Lyngb. [1819] 
Hydroph. Dan. p. 99 (Etym. plocamion opus textum), Harv. Crypt. 
Antarct. p. 75, Phyc. Brit. tab. XLIV, J. Ag. Sp. II, p. 592, Epier. p. 935, 
Schm. et Hauptfl, in Engl. & Prantl Natürl. Pflanzenf. (1897) p. 404, 
Thamnophonra Ag. [1822] Sp. I, p. 225, Kuetz. Sp. (1849) p. 887, 
Thamnocarpus Kuetz. [1848j; Phyc. gener. p. 4250, t. 59, III, Sp. 
(1849) p. 886 (non Harvey 1844), Plocas ''arg.-Tozz.|1819] in Bertol. 
Amoen. ital. p. 305, Nereidea Stackh. [1809] in Mém. Soc. Mosc. 
II, p. 58, 86 (non Ner. II, p. XXII), Delesserice, Fuci, Spherococci sp. 
— Frons membranaceo-cartilaginea, pinnatim decomposita, pinnis al- 
terne geminis ternis quinisve, duplici aut triplici strato constituta, 
cellulis interioribus longitudinalibus oblongis, axillaribus tenuiori- 
bus costam in nonnullis formantibus, corticalibus rotundato-angu- 
latis. Cystocarpia aut ad marginem sessilia singula aut in axillis ag- 
eregata, pedicellata, subsphzerica, intra pericarpium crassum, car- 
postomio munitum cellulisque extrorsum radiantibus, introrsum 
concentricis contextum, nucleum simplicem aut lobatum foventia; 
nucleus fundo basali impositus, placentaribus filis paniculato-ra- 
mosis lobos sustinentibus; lobi circa placentam radiatim dispositi, 
juveniles filis artieulatis ramosis constituti, maturescentes obco- 
nico-rotundati, carposporas plurimas rotundato-oblongas, sine or- 
dine conspicuo conglobatas quasi muco cohibitas foventes. Tetraspo- 
rangia in sporophyllis propriis evoluta, longitudinaliter biseriata, 
oblonga, zonatim divisa. Antheridia in soros superficiales evoluta, 
e cellulis hyalinis minutis constituta. 
Obs. J. ^gardh, op. cit., nonnullas de P/ocazo perutiles ob- 
servationes congessit, quas hie resumendas censeo, F rondes pulchre 
coccinee, tenue menmbranaces, nonnulli? demum firmiores, ille 
omnino ecostatse, hie aut costatz, costà ad pinnas extensá, aut an- 
cipites et margine destitutz», subcartilaginez:, omnes lineares pin- 
natim decomposite. Pinnae duplicis generis: primariw simplices, 
sepe subulats», in rachide distiche altern:e, interiore margine inte- 
gerrim:e, exteriore aliquando serrat:, secundariw pinnulat:e et de- 
compositz: supra axillas primariarum singule aut 2-4-seriatee. Aut 
itaque paria pinnarum (par quodque ex primaria et secundaria 
compositum), aut pinns tergemin: pluresve (infima nempe prima- 
ria, sequentes, quotquot sunt, secundarie) in utroque margine al- 
ternant, Sequenti autem modo et ordine pinns, ut videtur, oriun- 
tur. Primarie pinn:, prima et secunda, primum formantur; in 
hujus seeund: axilla secundaris, una pluresve, dein evolvuntur; 

