SECTIONAL TRANSACTIONS.- K. 391 



locally dominant : Typha australis (very closely allied to T. latifolia and T. angusti- 

 folia), Phragmites communis (apparently the form of southern Europe), Scirpus 

 macrocarpus (looking like <S. lacustris), and Cyperus j'astigiatus. Of plants with 

 floating leaves, Limnanthemum ihunbergianum (allied to L. peltatum) is abundant in 

 Florida Lake. Submerged plants occur, such as Potamogeton javanicus (with a few 

 floating leaves), and P. badius (alhed to P. ptisillus), P. sp. nov. The margin is rich 

 in marsh species, including Juncus effusus, J. spp., Raminculns sardous (agg.), 

 B. meyeri var. transvaalensis, Nasturtitim offtciyiale, and Epilobhim villosum (aS.A, 

 hirsutum). Spergularia (afif. S.marginata) sp. n. occurs on the margin of GeduJdLake. 



(3) Pans, or shallow depressions whose origin is in dispute. The pans are fre- 

 quentl}' dry in winter. However, ' Lake ' Chrissie, in the eastern Transvaal, is a 

 pan containing permanent water. The pans have a typical and characteristic 

 marginal flora, %vith Spergularia sp. n. (aff. 8. salina), L.essertia sp. n., Cuncuta sp. n., 

 and others. Lenina ' minor,'' L. ' gibba,'' and Wollfia arhiza occur locally in the pans 

 of the East Rand. Potamogeton peciinalus var. and Zannichellia repens occur in 

 Brakpan. Potamogeton livingstonii is abundant in Lake Chrissie and some adjacent 

 pans. The pans have a rich plankton, consisting chiefly of Copepods and Diatoms : 

 Volvox (a large species), and Hydrodiction (probably the recently described H. indicum) 

 occur in Reitfontein pan. The pans have no streams flowing out of them, and 

 consequently their mineral content is high, becoming almost supersaturated as 

 the dry season approaches. Incrustations of salts are of common occurrence on the 

 receding margins of the pans, as the waters are drying up. 



(4) Streams and their backwaters. Batrachospertnum sp. occurs in several of the 

 streams. The backwaters have the same flora as the lakes ; and the stream-banks 

 yield the same plants as the margins of the lakes. 



Mrs. M. Moss. — A Revision of the Genus Gnidia. 



In the course of this investigation, it has been found necessary to take the broad 

 view of Gnidia, as given in the Pflanzenfamilien. As understood by the present 

 author, Gnidia includes Arthrosolen, Lasiosipkon, and even Englerodaphne. Thus 

 defined, Gnidia contains nearlj' 150 species which range from Cape Town, through 

 the whole of South Africa (including the Karroo), Madagascar, central Africa, to 

 India, These species form a natural genus, and show such close intergradings that 

 no definite or constant characters have been found which warrant any subdivision 

 into smaller genera. 



Taxonomically, the genus is at present in a very confused state. This is partly 

 due to insufficient study of the type-specimens of the older species of Linnaeus, Linn. 

 fil., Thunberg, and Lamarck. It is also partly due to the making of new genera and 

 new species on the study of insufficient material. Sharp distinctions which appear 

 to hold when one or very few specimens are studied are often found not to hold when 

 a more extended study is made. The group is undoubtedly plastic ; and its members 

 appear to hybridise rather freely. There need be no doubt as to the common origin of 

 all the species. 



Certain evolutionary tendencies are apparent, but are not constant or important 

 enough to be of generic value. 



The revision has entailed a study (including work on comparative anatomy) of 

 such a large mass of material that probably the results will be pubhshed in three 

 parts : (1) the species of the Transvaal and the Orange Free State, (2) those of the 

 Cape of Good Hope and Natal, and (3) those of Madagascar, Central Africa, and India. 



Prof. C. E. Moss. — The Genus Anthericum in South Africa. 



Miss D. M. Welsh.— TAe Anatomy of African Species of Salicornia and 

 Allied Genera. 



The late Dr. Ethel de Fraine investigated the anatomy of the glassworts of 

 western Europe. The present work is on similar fines, but appfies to the glassworts 

 of Africa. In each case, the work was done in connection with taxonomic work on 

 the Salicorniece by Professor Moss. 



The genera investigated by Dr. de Fraine were Halocnemum, Arthrocnemum, and 

 Salicornia. To these, the present work adds the alternate-leaved Halopeplis. 



The African species investigated comprise Salicornia sp. n. A, <S. perrieri. 



