I O.'l 2 



\oi'se ilis|)(isilis, l'I oiim animlo sci'ul)iciiliiiiiiii iiiiiHiloiimi i)-iu cirra \L'iiiii\iin iiiuiiii- 

 qiienujue : a vcrlifc \is;i' suliellij)tic;i', polis ti'diuMtis, ail aiig'tilimi iimim(]uetii(|ue spiiia 

 siibiilala Icviler ciirvala paiillo diverueiUe, laleiiuus coiive.xis, verriicis rotuiulatis bitiis 

 ail mocliuiii utrohicjiie, seiie siil)irrt'iJiilariler ciisposila spiiiaiiiin 'i iiitia iiiarg-iiiein lale- 

 ralcni uiuiiii(|uemqiie ; inemhraiia ilelicate puiictulata. 



Long-, sine s[)in. 73 u., c. spiii. lyi a; lai. siiit- spin. Go a, c. spin. 85 [j.; ial. istluii. 

 21 [1.; crass. !\-> y. (IM. XX'II, lli;-. !\i). 



CiiiuliiKunarca : L\vi,u\v,\ de l'haipie, EasU'in Andes; allil. :»o(i(i m. X" ■>'.\. 



\\\ tliis species lliere are seven pairs aï spines on eacli semicell, one pair at eaili of 

 llie latéral and a[»ical angles, one pair in ihc niiddle of (lie apex, and one paii' in llie 

 middie of eacli npper latéral margin. 



The gênera! outline of llie cell reseinliles ihal of A', (inlUojxicuin ( liiii'.ii. 1 Kutz. , froin 

 ^\ liicli X. MdijOfi dilfers in ihe lliree addilioiial [lairs (jf s|)ines and in tlie présence of 

 tlie liina^e central verriicic. 



249. Arthrodesmus Iiicus 1 Bréb.) Hass. forma minor W. and G. S. \\'r:si-. — 

 Anlioquia : u"^ i and 2. 



200. Arthrodesmus controversus N\'. and G. S. Wiîsr. — Anlioquia : n» 8. 



261. Arthrodesmus convergens Ehrenb. — Anlioquia: n» 5. 



252. Arthrodesmus bifidus Hréb, — Anlioquia: n» 5. 



2Ô3. Staurastrum antioquiense spec. nov. 



S. minutissimum, ciiciter lam longurn quam latum (cum processibus), profunde 

 conslrictum, sinu valde aperlo ad e.xlremuin acuminato; semicellulie Iransverse elliplica', 

 polis in processus brevissinius submamillatos bis[>inaloshorizontaliler disposilos productis, 

 ad apiceni conve.xum processibus brevissimis submamillatis bispinulatis 3 priedila'; a ver- 

 tice viste sexangulares, ialeribus concavis, angulis rolundato-mamillalisel bispinalis, inlra 

 sed juxla margines processibus brevissimis bispinulatis 3; menibrana tenuissima et glabra. 



Long, sine j)roc. i3,.^ [j-, c. proc. 17,6 p.; Ial. (c. proc.) 16-17, ,5 ^- ! ''*'• isthm. 5,3 [^. 

 (PI. XXI, fig. 29). 



Anlioquia : Laguna above Medeliin, Central Andes ; allit. 23oo m. X"^ i and 2. 



Tliis minute Staurastrum resembles in ils front view some of the smaller for'ms of 

 St. fnrcatuin Ehrenb., but is much less. The vertical view is al once distinclive, since 

 it is ô-ang-ular, with six equal mamillate processes in the lower vvhorl and onl}' three 

 apical ones, one of the laller occurring jusl within each alternate concave side. 



254. Staurastrum arcuatum Nordst. 



Forma semicellulis robuslioribns, angulis crassioribus ; islhmo laliori. Long, sine 

 spin. 28 [ji.; lat. c. spin. 46 f*; 'al. islhm. 12 (a. — Anlioquia ; n»» i and 2. 



255. Staurastrum brachiatum Ralfs. — Anlioquia : n'" i and 1. 



256. Staurastrum brevispiuum Buiîb. var. inerme VVille. 

 Long. 66-74 ,".; lat. 54-61J [j. \ lai. isllim. i4-i5 u.. 

 Gundinamarca : n° 24 (fréquent). 



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