

924 Conjugatae, Desmidiaceae, Xanthidium. 



minoribus, spinis tenuioribus in basi non dilatatis, semiceilulis lon- 

 gioribus incisura acutangula disjunctis. 



12. Xanthidium Smithii Archer in Micr. Journ. VIII, p. 238, t. XI, 221 

 f, 10-12, Pritch. Inf. p. 736, Rabenh. Fl. Eur. Algar. III, p. 224, 

 Cooke Brit. Desm. p. 133, t. 45, f. 4. — Parvum, 21 ^ 19, e fronte psene 

 tam longum quam latum, leve ; constrictione acute cuneata; semi- 

 cellulis trapezoideis, diaraetro subduplo longioribus, angulis rotun- 

 datis in aculeos geminatos, breves, acutos productis ; e dorso oblon- 

 gis, utroque polo truncatis et triaculeatis; tuberculo centrali mi- 

 nuto, 



Hab. ad Dublinum in Hibernia (Archer). — Var. variabile 

 Nordst. Freshw. Alg. of N. Zeal. and Austral. p. 44, t. 4, f. 27-29, 

 Botaniska Notiser 1887, p. 159 et Notarisia 1888, p. 413: semicel- 

 lulis basi subrectis, constrictione cellula3 minus cuneata, apice trun- 

 catis vel leviter retusis ; a vertice et a basi visis apicibus trunca- 

 tis, angulis 1-2-aculeatis, interdum aculeo inter angulos ornatis, 

 medio utroque latere tumore rotundato-truncato vel aculeato pr^e- 

 ditis; a latere visis utrinque turaore rotundato vel biaculeolato 

 prseditis; aculeis parvis ad 4 ij.. iongis; long. sin. acul. 24-32 u.., lat. 

 22-28 u.., lat. isthm. circ. 8 ij.., crass. 16-J8 u., long. acul. c. 4 p.. 

 Ad «Arthur Pass, Teremakau et Arahura» in Nova Zelandia (S. 

 BergCtREn) — Forma lateribus semicellularum pauUulum retusis 

 Nordst. 1. c. t. 4, f. 29: long. sin. acul. 34 u.., lat. 28 (j.., crass. 18 p.. 

 Ad «Teremakau et Arahura» in Nova Zelandia (S. Berggren). 



13. Xanthidium Robinsonianum Archer in Micr. Journ. XX (1880), 22ir 

 p. 114, Cooke Brit. Desm. p. 134. — Parvum; seraicellulis trape- 

 zoideis, angulis rotundatis, spinis paucis rainutis coronatis; inflatio- 



ne mediana semicellularum granulis paucis irregulariter dispositis 

 munita; marginibus inferioribus rectis, isthmo leniter elongato, 

 Hab. in stagnis Hiberniae (Archer). 



14. Xanthldium simplicius Nordst. Freshw. Alg. of N. Zeal. and Au- 2217 

 stral. p. 44, t. 4, f. 26, Botaniska Notiser 1887, p. 159, Notarisia 

 1888, p. 413. - Parvum, tara longum quam latum, medio profunde 

 constrictum, sinu mox valde dilatato; semicellulis e basi convexo- 

 subcuneata transverse subrectangularibus, apicem versus quam 

 levissirae angustatis, angulis superioribus et inferioribus aculeos 

 parvos singulos vel binos gerentibus ; a vertice visis ellipticis, api- 

 cibus non latis truncatis, medio utroque latere tumore parvo; a 

 latere visis subhexagoniis, apice truncatis, lateribus obtusis. 



Hab. ad u Taupo, Oraatangi » in Nova Zelandia (S. Berggren). — 



