4 
Transactions of the Society. 
II. — Freshwater Alyas and Schizophycese of South-west Surrey. 
By Alfred W. Bennett, M.A., B.Sc., V.P.L.S., V.P.R.M.S., 
Lecturer on Botany at St. Thomas’s Hospital. 
(Read 18 tli November, 1891.) 
Plate II. 
The district worked over in the observations recorded in this paper 
is a small area in Surrey, bordering on Hampshire, between Fren- 
sham to the north and Haslemere to the south, the greater part of it 
at a considerable elevation, rising to 900 feet at the summit of Hind- 
head. The geological formation of the whole of this area is the 
Lower Greensand, and the soil uniformly a ferruginous sandstone, a 
soil very unfavourable to the formation of true bog, and hence of the 
numerous algae — especially desmids — which rejoice in peat-bogs. 
True Sphagnum-hogs occur in the “ Devil’s Punchbowl,” a locality 
exceedingly well-known to botanists, and one of great beauty and 
wildness ; near the “ Devil’s Jumps,” two remarkable isolated hills to 
the north of the Punchbowl ; on Frensham Common, and elsewhere; 
but they are of small extent. The two large ponds at Frensham — 
the larger one almost meriting to be called a lake, and also well- 
known to botanists — and some mill-ponds near Churt, also yielded 
some interesting algae. But, on the whole, the country is a barren 
one both from a phanerogamic and a cryptogamic (except mycological) 
point of view ; and the number of new species or forms observed is 
small. The valley of the Wey was not visited. The summer was 
an exceedingly rainy one ; and this also is unfavourable to the collec- 
tion of Freshwater Algae, in two ways. It renders the true bogs more 
difficult of access. Furthermore, according to my observation, conju- 
gation takes place, in the Zygnemaceae and Desmidiaceae, most freely 
when the conditions of vegetative life are unfavourable, especially 
when the supply of water or of moisture is limited. 
rig. i- 
„ 2 .- 
:: I:} 
„ 5- 
„ 6.1 
„ 7.1 
„ 8 .- 
„ 9.- 
„ 10 .- 
„ 11 .- 
» 12 .) 
„ 13./ 
„ 14.- 
15.- 
EXPLANATION OF PLATE II. 
-Trocliiscia pachyderma (Reinseh) Hansg. (x 400). 
-Gkeotrichia Pisum Thur. (x 400). 
Pediastrum gracile A. Br. ; marginal cells ( X 500). 
„ glanduliferum sp. n. ; portion of ccenobe ( x 400). 
„ „ „ marginal cells ( x 800). 
-Tetmemorus minutus DBy., front view ( x 400). 
„ „ „ side view ( x 400). 
-Micrasterias rotata Pdfs. var. acutidentata var. n. ( x 200). 
-Cosmarinm minutum sp. n. ( x 400). 
„ Ungerianum (Nag.) Arch, (x 200). 
„ Westianum sp. n. ( x 300). 
-Calocylindrus connatus Kirchn. ( x 200). 
