— io4o 



Var. montanum Sc.ii.midle. — Aiilinqiiia : iv* i anil •>. 



234. Cosraarium repandum Nordst. toniiii minor W . iind <!. S. West (= (J. odo/i- 

 tdpleiiriint Knv aiid Biss.). — Aiiliniiiii.i : w 'j. 



235. Cosmarium retusiforme (^Wii.i.ici Llurw. forma abscissa (Sciuiidli;) Boige. — 

 Anlioqiiia : n"* i aiiil i>. CuiKlinaiiiarca : n» 23. 



236. Cosmarium retusum (Peuiy) Rabenu. var. inaequalipellicum \\ . aTul (!. S. 

 West. Mon()i;r. Bri(. Dcsin. III, 1908, p. 267 (:= C. in<ieijU(ilipeUii'uiu \\ . and (i. S. 

 West, i8()5). — .Viili(>i|iiia : rv* i, 2, 3, 4 aiid 8. 



237. Cosmarium subaequale Sp. nov. 



C. subincdiiicro, rircilcr i ' o-plii long'iiis (jiiaiii latnin, pi'ol'iiiulissiiUL' constriclum, 

 sirui anij'iislo-liiieari ad cxlremuni .siibatnpiialo ; .seinicelluhi' li'iangidares, base rccla, 

 aiii>ulis iiil'eriorihus laie rotutidalis et in parte superiori curn nndiilo \\\ conspiciio, lalo- 

 ribus concavis, ang-ulo apicali late rolmidalo et ad apiceni cuni inembrana incrassala ; in 

 centro semicellidarum tumoribus parvis tribus, tumore uno juxta istlimum et lumoribus 

 binis superioribus honzontaliter disposilis ; a lalcre visa? ovato-pyramidatœ, angulis 

 basalibus rotundatis, iateribus cum tumore depresso et parvo infra médium, apicc late 

 rolundato; a verlice visœ ellipticte, polis rotundatis, tumoribus parvis tribus ulrobique; 

 niembrana punctata, punctis ad angulos semicellularum majoribus. Pyrenoidibus binis. 



Long-. 64 p.; lat. 39 \J.\ lat. apic. i4 \>-', lat. isthm. i3 [/.; crass. 28 (;.. (PI. XXIIl, 

 fig. 63). 



Anlioqnia : In ditches between Medellin and America, Central Andes; ailit. i,^)5o m. 

 i\o 6. 



This species is a close ally ol' C. aequnle Turner (in K. Sv. Vel. Akad. Ilandl. 

 Bd. XXV, n» 5, 1893, p. 64, t. n, f. 3i), but is distinguislied by ils larger size, ils 

 proportionately longer cells, ils ihree central tumours (which cause ihc side and vertical 

 views to be entireiy ditTerent), and by ils conspicuously punctate cell-vvall. Borge lias 

 recorded C. aequale hom Argentina (cfr. Arkiv for Botanik ulgifv. K. Sv. Vet.-Akad. 

 Bd. VI, 1906, p. 7 c. fig.) and he describes and figures llie semiceils as having a chloro- 

 plast willi one central pyrenoid. In C. siibaeqiiale ihere are Iwo pyrenoids in eacli 

 semicell. 



238. Cosmarium subarctoum (Laoerh.) Racib. ; W. and. G. S. West, Monogr. 

 Bri(. Desm. 111, 1908, p. 3i, t. 68, f. 6-8. 



Var. minutissimum var. nov. 



Cellulœ minutissim;c, semicellukc, ad isthmum plus minusve torta-. 



Long. 6,.5-6,8 |y.; lat. .5,6-6 ;;. ; lat. isthm. 2,8 \^.\ crass. 3,4-3,7 [/• (Pi. XXII, fig. 46-47)- 



Anlioqnia: Laguna above Medellin, Central-Andes ; altit. 23oo ni. n*"* i and 2. 



This variely is one of ihe very smallest of known Desmids. Il is aboul one-third 

 ihe size of lypical C. subarctoum, but is otherwise in no vvay différent l'rom tlial s[)ecies, 

 llie cells of which, as in this Columbian variely, are oflen slightly twisled at tlic islhmus. 



Among other minutespecies o'i Cosmarium should be mentioned C. suevicum Kircuner 



