Fresh-water Algce. 87 



141. Cosmarium Pappekuilense, (J. S. West, sp. n. 



C. parvum, eircitor tarn longum quam latum, profundissime 

 constrictum, sinu acutangulo et aperto ; sernicellulas transverse 

 suboblongae, margine ventrali loviter convexo, margine dorsali 

 (apice) recto, lateribus rotundo-convexis ; semicellulas a latere visas 

 subcirculares ; a vertice visas oblongas, polis rotundatis, lateribus 

 subrectis ; membrana minute granulata, granulis in seriebus verti- 

 calibus cire. 15 dispositis, 7-8 in serie unaquaque, chromatophora 

 singula axiali in semicellula unaquaque, cum pyrenoide centrali, 

 in lobos radiatos subangustos subirregulariter producta. 



Long. 27// ; lat. 27-28-5 ft; lat. isthm. S/x; crass. 13 /i. (Fig. 40.) 



Karoo. In sulphureous spring at Pappekuil ; 2.12.08. 



In general outline this species agrees most closely with C. biocu- 

 latum, Breb., var. hians, W. & G. S. West, but differs in its larger 

 size, its distinctly granulate cell-wall, and in the irregularly lobed 

 chloroplasts. From C. Wittrochii, Lund., it differs in its oblong 

 semicells, both in front and vertical views, and in its much finer 

 granulation. Tbe form of the front view is also very like that of 

 C. staurastroides, Eichl. & Gutw., but its other characters are 

 quite different. 



142. Cosmarium Pearson/'., G. S. West, sp. n. 



C. mediocre, circiter 1^-plo longius quam latum, profundissime 

 constrictum, sinu angustissimo-lineari ad extremum ampliato ; semi- 

 cellulas subsemicirculares, apice indistincte et subanguste truncato, 

 angulis basalibus leviter rotundatis ; a latere visas circulares ; a 

 vertice visas subanguste ellipticas ; membrana dense granulata, 

 ad marginem semicellulas uniuscujusque circiter 48-50, granulis 

 parvis margines versus in seriebus confertis verticalibus ordinatis, 

 centrum versus granulis paucioribus et irregulariter dispositis ; 

 pyrenoidibus binis in semicellula unaquoque. 



Long. 73/x ; lat. 62-64 F ; lat. isthm. 22 A < ; crass. 35 y. (Fig. 42.) 



Upper (or Composite) Eegion. Holle Eiver, in drying mud in the 

 river-bed ; 10.12.08. 



This species should be carefully compared with C. Botrytis var. 

 depressum, W. & G. S. West, from which it is distinguished by 

 the density and disposition of its smaller granules. 



143. Cosmarium pramorsum, Breb. 



Forma cellulis paullo longioribus ; long. 55-60 jj. ; lat. 43-46 yu ; 

 lat. isthm. 13/<. 



Great Namaqualand. Abundant in a cattle-trough at Griindoorn ; 

 4.2.09. 



