THE FRESH-WATER ALGAE OF ESSEX. 171
Tetraspora bullosa, Ag. Cooke, t. 6, f. 1. In pools,
Messing (E.G.V.).
T. lubrica, Roth. Cooke, t. 6, f. 3. In ditches, Kelvedon ;
Rivenhall (E.G.V.).
T. gelatinosa, Vauch. Cooke, t. 6, f. 2. In ditches, Kelve-
don (E.G.V.).
Apiocystis brauniana, Nag. Cooke, t. 7, f. 1. In ditches,
etc., Snaresbrook.
Rhaphidium falcatum, Corda. Cooke, t. 8, f. 4. In pools,
Snaresbrook.
PROTOCOCCACEAE.
Protococcus viridis, Ag. Cooke, t. 12, f. 1. On trunks,
etc., Epping.
Chlorococcum gigas, Green. Cooke, t. 12, f. 3. In pools,
Walthamstow.
Scenedesmus obtusus, Mey. Cooke, t. 13, f. 5. In boggy
pools, Snaresbrook.
S. acutus, Mey. Kelvedon (E.G.V.). Var. obliquus. Cooke,
t. 13, f. 6c. In pools, Snaresbrook.
S. quadricauda, Breb. Cooke, t. 13, f. 8. In standing water,
Snaresbrook.
Hydrodictyon utriculatum, Roth. Cooke, t. 14, f. 1. In
clear water, Kelvedon (E.G.V.).
Pediastrum boryanum, Turp. Cooke, t. 16, f. 11. In
pools, Loughton (Q.M.C.).
P. rotula, Ehr. Cooke, t. 18, f. 2. In pools, Snaresbrook.
Hydrianum heteromorphum, Rein. Cooke, t. 19, f. 6.
Attached to Algae, Snaresbrook.
VOLVOCINEAE.
Chlamydococcus nivalis, Br. Cooke, t. 21, f. 2. On
snow, Forest Hill ("Daily News," Mar. 14, 1876) [? Essex.—Ed.]
Volvox globator, Linn. Cooke, t. 22, 23. In ponds,
Epping ; Loughton : Snaresbrook.
V. minor, Stein. Cooke, t. 25. In ponds, Epping (Q.M.C.).
Gonium pectorale, Mull. Cooke, t. 27, f. 1. In pools,
Loughton ; Snaresbrook.
Eudorina elegans, Ehr. Cooke, t. 26. In ditches, Abridge.
DESMIDIEAE.
Sphaerozosma secedens, D. By. Cooke, Desm., t. 2, f. 3.
In pools, Snaresbrook.