Freshwater Algae of 8. of England. By W. <4* G. 8. West. 507 
The discovery of this genus necessitates the modification of the 
Fam. Camptotrichese as follows : — 
Fam. Camptotriche^:. Fila epiphytica et aquatica, brevia 
vel longa, vaginata, haud ramosa, irregulariter flexuosa, ex- 
tremitates ambas versus attenuata, serie singula cellularum 
intra vaginam unamquamque formata, vaginis delicatis vel 
firmis, achrois vel luteo-fuseis. 
Gen. 1. Camptothrix. Fila brevissima, e serie 
singula cellularum irregularium formata, extremitates 
versus paullo attenuata, submoniliformia ; vagina deli- 
cata et hyalina ; protoplasma cellularum homogeneum. 
Gen. 2. Ammatoidea. Fila longa, e serie singula 
cellularum regularium formata, subito genuflexa, in 
medio et extremitates versus longissime attenuata ; 
vagina firma et saepe luteo-fusca ; protoplasma cellu- 
larum granulosum. 
Fam. Vaginarieae. 
Genus Schizothrix Kiitz. 
1*. S, vaginata (Nag.) Gomont. 
Articuli saepius diametro trichomatis paullo longiores. 
Crass, trich. 2*5-3 /i. YI. N. 
Genus Dasygloea Th waites. 
1. D. amorpha Berkeley. III. Th. (a form with thinner tri- 
chomes). YI. N. 
Fam. Lyngbyeae. 
Sub-fam. Lyngbyoide^:. 
Genus Lyngbya A g. 
*1. L. putealis Montagne. III. Bp. 
2. L. Martensiana Menegh. III. Dj. 
*3. L. eerugineo-ccerulea (Kiitz.) Gomont. III. Kingston to 
Esher. 
*4. L. versicolor (Wartm.) Gomont. III. Dorking. 
5. L. ochracea (Kiitz.) Thur. III. Cr. 
Sub-fam. Oscillatorioide^:. 
Genus Phormidium Kiitz. 
*1. P. niolle (Kiitz.) Gomont. III. Bp. (on Myriophyllum). 
*2. P. foveolarum (Mont.) Gomont. III. In chalk pit, Dorking. 
*3. P. tenue (Menegh.) Gomont. II. Pi. III. Bi., Fg., Wi. 
IY. He. 
4. P. autumnale (Ag.) Gomont. III. Wi. Esher, Thames 
Ditton, Kingston. 
