36 wklwitsch's African freshwater alg^. 



2. Cladophora Kiitz. (1843). 



1. C. CRisPATA (Roth) Kiitz. Phijc. Gener. 264 (1843) ; Cooke, 

 BHt. Freshiv. Alg. 143, t. 55, fig. 3. A form with the filaments not 

 more than 1-li cm. high ; branching suhdichotomous, subsecund 

 towards the apex ; cells 6-12 times longer than broad. 



Loanda. From the bottom of the well at Welwitsch's house in 

 Loanda; Jan. 1859. No. 144. 



2. C. amplectens Welw. MS. ; name with partial description. 

 0. ctespites duriusculos rigidos formaus, laete virides, diametro 

 circiter 12-15 cm., ericaceo-hiapidulos, basin truncorum prope 

 terram limoso arenosam circa circum amplectentes ; filis carti- 

 lagineo-elasticis, dense intertextis, subdichotome et sparsim ramosis, 

 cellulis plerumque diametro 20-plo (vel usque) longioribus ; ramis 

 paullo angustioribus quam filamenta primaria, cellulis diametro 

 14-20-plo longioribus, granulis intense viridibus laxe repletis ; 

 cellulis teiminalibus obtusis ssepe subclavatis ; membrana delicate 

 plicato-striata. Crass, fil. prim. 100-150 fj.; crass, ram. 75-92 /j.. 



Loanda. Ad imam basis truncorum lihizophoranun tempore 

 refluxus oceani aeri expositarum ad littora Loandeusia frequens ; 

 Nov. 1853. No. 23. 



This species belongs to the section (Egagropila, and has rather 

 a peculiar habit ; Welwitsch likens the appearance of a tuft to that 

 of a child's head. 



3. Cladophora sp. A minute fragment, insufiicient for accurate 

 determination; filaments about 1-5 mm. in length, branched re- 

 peatedly and irregularly ; cells 1^-3 times as long as broad, mostly 

 somewhat inflated, terminal cells acutely conical. Crass, cell. 

 33-56 /x. On Helices in Lagoa de Quibonda; Sept. 1857. No. 200. 



VIII . — Pithophorace^e . 

 1. PiTHOPHORA Wittr. (1877). 



1. P. radians, sp. n. P. gracilis et radiata, elegantissima (13-18 

 cm.) ; foliis primariis plantarum fertilium thalli cauloidei crassitudine 

 circiter 114 /^ (104-130 jx) ; ramos ordinis primarii etiam paucos 

 ordinis secundi (crass, circ. 64 /x) gereus ; cellulis vegetativis 

 diametro 6-16-plo longioribus; sporis solitariis, intercalaribus 

 termiualibusque ; sporis intercalaribus subcylindricis et leviter 

 iuflatis, long. 150-200 /x, lat. 100-120 /x ; sporis terminalibus 

 ovato-ellipticis base truncato, apice conico et obtuse subacuminato, 

 long. 200-266 /x, lat. 91-116 /x ; sporis subfrequentibus his locis 

 ubi rami oritur. 



Loanda. Copiose in aquariis aquae subdulcis insulns Cassanga 

 prope Morro da Cruz ; April 1854. No. 197. " Stirps vegetationis 

 suae luxuria et vitae fugacitate aeque insignis." 



The nearest species to this is P. G^Jdogonia (Mont.) Wittr., from 

 which it differs in its much greater thickness, in having no branches 

 of a third order, in never having binate spores, and in the inter- 

 calary spores being much less inflated. 



