120 WELWITSCh's AFRICAN FRESHWATER ALG.E. 



35. C. AFFiNE Eacib. in Bospratvy Akad. Umiej. Krakow, Wydzial. 

 viat.-przyr. ser. 2, t. ii. (vol. xxii.) 363, t. vi. f. 25 (1892). 



Var. AFRicANUM, vav. n. (tab. 368, fig. 7). Var. minor et 

 augustior ; membrana glabra. Long. 12-5-14 /x; lat. 9'5-10-5 /x; 

 lat. isthm. 6'5-7'5 fx. 



Libongo. Ad margines flum. Lifune ; Sept. 1858. No. 201. 



36. C. BiiNUTissiMUM Arcb. in Q. J. If. S. xvii. (ueAV ser.) 194 et 

 301 (1877); Cooke, Brit. Desiii. 91. The identification of this is 

 somewhat uncertain, owing to Archer's meagre description ; the 

 following is a description of the plants seen : — 



C. minutissimum, circiter l^-plo longius quam latins, profunde 

 constrictum, sinu liueari extremo ampliato ; semicellulffi elliptico- 

 semicirculares ; a vertice visse ellipticre ; a latere visse siibglobosae ; 

 membrana achroa et glabra. Long. 11 /x ; lat. 8 /i ; lat. isthm. 2 fx ; 

 crass. 5 /x. 



Hiiilla. Morro de Lopollo ; May 1860. No. 182. 



37. C. galeatum, sp. n. (tab. 368, figs. 2, 3). C. parvum, sub- 

 duplo lougins quam latins, profunde constrictum, sinu lineari 

 extremo valde ampliato ; semicellulfe semiellipticfe, apicibus sub- 

 truncatis, angulis inferioribus leviter rotundatis, angulo unoquoque 

 dentem parvum gerente ; a vertice et a latere viste ellipticre ; mem- 

 brana glabra. Long. 20-22 /x ; lat. 11-5-13 /x ; lat. isthm. 3-5-4 /x; 

 crass. 7-5 /a. 



Huilla. Lopollo ; Febr. 1860. No. 192. 



The form of this species together with its small size and the 

 presence of a tooth at each basal angle easily distinguish it. 



88. C. Libongense, sp. u. (tab. 368, fig. 12). C. mediocre, 

 circiter 1^-plo longius quam latins, profunde constrictum, sinu 

 angustolineari, extremo subampliato ; semicellulte pyramidato- 

 semicirculares, angulis inferioribus subrotundatis, lateribus 4 

 (vel 5)-crenatis, apicibus truncatis rectisque ; a vertice vis^ sub- 

 angusto-elliptica3 ; a latere visa? late ellipticfe ; membrana dense 

 punctata. Long. 46-49 /x ; lat. 38-39 /x ; lat. isthm. 12-5-14-5 /j.; 

 crass. 20 /x. 



Libongo. Ad margines flum. Lifune ; Sept. 1858. No. 204. 



This difl'ers from C^. suhnndulatum Wille in its shorter cells, its 

 truncate apices, its crenate lateral margins, its entire absence of 

 granules, and in its difi'erent vertical and lateral views. From 

 C. suhnndulatum var. Beanlandii West it differs in its crenate lateral 

 margin, its more truncate apices, in the absence of granules, and 

 in its difi'erent vertical view. 



39. C. EEPANDUM Nordst. in Botan. Notiser, 1887, 162; in 

 A'. Sv. Vet.-Akad. Handl. Bd. 22, no. 8, 58, t. vi. f. 14 (1888). A 

 form with the semicells a little dilated upwards. Long. 56 /x ; lat. 

 45 /x; lat. isthm. 21 /x ; crass. 25 /x (tab. 368, fig. 13). 



Huilla. In uliginosis editioribus prope Humpata, Empalanca 

 et Lopollo ; May 1860. No. 15. 



C. odontopleurum Arch, (in Roy et Biss. in Ann. Scott. Nat. 

 Hist. (1894), 169, t. ii. f. 13) appears to be only a small form of 

 C. repandum Nordst. 



