36 



Journal of Travel and Natural History 



Fig. 3. — Shews the 

 Scytonema of its 

 natural size. 



larger plants, during the glowing heat of the following day. (The 



growth and thriving of numerous small Phanerogamous plants, from 

 the orders of Eriocaulonese, Cyperace^e, Cam- 

 panulacese, Scrophularinse, and Droseracese, nay, 

 even the existence of a few Isoeteae, in these 

 places, is conditional on the co-presence of the 

 prolific Scytonema. If they were to lose the 

 important hygroscopic protection of the latter, 

 they might be unable to thrive under the scourge 



of the tropical sun.) But these species, although all belonging to 



the genus Scytonema, are specifically quite distinct from those 



growing on the mountains of 



Pungo Andongo ; they are of 



brighter colour, and are spread 



like velvet, in a horizontal layer, 



over the soil. An exquisite 



species, bright red, I encoun- 

 tered abundantly, eastward of 



Pungo Andongo, between Condo 



and Quisonde, where it covered 



tracts of 20 to 30 paces, like a 



carpet, harbouring numerous 



small phanerogamic plants. Also 



on my later journeys to the 



Highlands of Benguella, and 



principally on the high plateau 



of Huilla, I often met with 



other species of Scytonema 



growing over the sandy soil of 



the pastures and open forests ; 



but nowhere did I observe these 



small cryptogamic plants in such 



abundance, nor their effect on the physiognomy of the country so 



striking, as at the Pedras Negras of Pungo Andongo. 



Fig. 4. — A branchlet magnified. It will be 

 described under the n.ame of Scytonema 

 chorographicum. 



