Var. elegans var. nov. 
Var. processible valde el elegante curvatis sursum ; ceteris ut in forma lypica. 
Long, sine proc. 38 p., cum proc. 69 p, ; lat. sine proc. cire. 18 p., cum proc. 70 p ; 
lat. isthm. 8,5 tx ; crass. 16 p. (PI. XXI, fig. 3 i). 
Cundinamarca : I11 the plankton of Laguna Pedropalo near Tena, Eastern Andes ; 
altit. 2000 m. N° 21. 
A ’ var. divergeas ‘ of St. leptocladum was figured by Wolle (Desm. U. S. 1 884 , 
t. 44 î f. 5 ) but theColumbian form appears to be something quite different. The outward 
curvature of the processes is exactly the saine as in St. leptocladum var. insigne W. and 
G. S. West. 
272. Staurastrum Mayori spec. nov. 
St. parvum, paullo longius quam latum, submodice constrictum, sinu aperlo et semi- 
elliptico; semicellulæ oblongo-subsemicirculares, apice subtruncato, ad angulos basales et 
in medio marginis lateralis uniuscujusque verruca truncata inslructæ, etiam ad apicem 
latum (et partira infra marginem) cum verrucis truncalis 4, seriebus duabus verrucarum 
trans semicellulam ; a vertice visæ triangulares, angulis verruca truncata instructis, 
lateribus leviter convexis cum verrucis truncatis 2. Dispositio verrucarum in seriebus 
horizontalibus tribus, in sérié infima 9, in sérié mediana 9, in sérié superiori 6. 
Long, cum verrue. 23,5-24,5 (x; lat. cum verrue 21-22 p. ; lat. isthm. i 3 jx (PI. XXI, fig. 32 ). 
Antioquia : Bog near the Laguna above Medellin, Central Andes ; altit. 23 oo m. N 5 . 
This species appears lo be very distinct by reason of the nature and disposition of 
ils truncate verrucæ, of vvliich there are three horizontal sériés on each semicell : 9 in the 
basal sériés, 9 in the médian sériés, but only 6 in the upper or apical sériés. 
In the outline of the cell St. Magori resembles the New Zealand St. dorsuosum 
Nordst., but the verrucæ on the two species are of a totally different character. 
273. Staurastrum muticum Bréb. — - Antioquia : n os 1 and 2. 
274. Staurastrum O’Mearii Archer. — Antioquia : n° 3 . 
27b. Staurastrum orbiculare Ralfs. — Antioquia : n° 5 . 
Var. denticulatum Nordst. — Antioquia: n° 4 - 
276. Staurastrum paradoxum Meyen var. longipes Nordst. — Cundinamarca : n° 21 
(plankton). 
277. Staurastrum pterosporum Lund. — Antioquia: n oS 3 and 5 . 
278. Staurastrum quadrangulare Bréb. forma trigona. Long. 26-28 p. ; lat. 25-28 p. ; 
lat. isthm. 8-9 p.. 
Antioquia : n° 5 . 
279. Staurastrum retusum Turn. (inclus, var . punctulatuni Gutw.) — Antioquia : n os 1 
and 2. 
280. Staurastrum Rotula Nordst. — Antioquia : n° 5 (abundant). 
281. Staurastrum senarium (Ehrenb.) Ralfs; G. S. West in Journ. Linn. Soc. 
Bot. XXXIX, 1909, p. 68, t. 6, f. 1 3 . — Antioquia: n° 5 . 
