174 THK FRESH-WATER \\J;.V. OF ESSEX. 



C. margaritiferum, Turp. Cooke, Desm., t. 39, f. 2. In 

 ponds, Wood Street, Walthamstow ((^.M.C.)- 



C. botrytis, >ren. Cooke, Desm., t. 39, f. 4. In pools, High 

 Beach (A.H.H.) ; Snaresl)rook. 



Xanthidium armatum, Tireh. Cooke, Der,ni., t. 45, f. i. 

 In ponds, High Beach (A.H.H. ). 



Arthrodesmus octocornis, Ehr. Cooke, Desm., t. 47, f. 2. 

 In ponds, Snareshrook. 



A. incus, Hass. Cooke, Desm., I. 17, f. 4. In ]ionds, Snares- 

 brook. 



A. convergens, Ehr. Cooke, Desm., t. 47, f. 1. In ponds, 

 Chingford ; Snareshrook. 



Staurastrum dejectum, Breb. Cooke, Desm., t. -19, f. i. 

 In ponds, Snareshrook. 



S. cuspidatum, Breb. Cooke, Desm., t. 49, f. 5. In ponds, 

 Snareshrook. 



S. orbiculare, Ralfs. Cooke, Desm., t. 51, f. 7. In ponds, 

 Loughton. 



S. muricatum, Breb. Cooke, Desm., t. 54, f. 5. In pools, 

 High Beach. 



S. punctulatum, Breb. Cooke, Desm., t. 54, f. 6. In ponds, 

 Chingford ; Snareshrook. 



S. alternans, Breb. Cooke, Desm., t. 54, f. 7. In ponds, 

 Snareshrook; High Beach (A.H.H.). 



S. polymorphum, Breb. Cooke, Desm., t. 58, f. 4. In 

 ponds, Chingford. 



S. arachne, Ralfs. Cooke, Desm., t. 63, f. 4. In ponds, 

 Snareshrook. 



ZYGNEMACE3;. 



Zygnema cruciatum, Vauch. Cooke, t. 30, f. i. In ditches, 

 Snareshrook ; High Beach. 



Z, vaucherii v. sfag/ia/c, Hass. Cooke, t. 30, f. 5. In 

 pools, High Beach. 



Z. anomalum, Hass. Cooke, t, 31, f. i. In pools. High 

 Beach (A.H.H.) ; Easthorpe (E.G.V.). Var. lutescens, Hass. In 

 pools, A\'est Bergholt Heath (E.G.V.). 



Spirogyra crassa, Kutz. Cooke, t. 32, f. i. In pools, 

 Colne (E.G. v.). 



S. nitida, Dill. Cooke, t. t^^^ f. i. In ponds, Kelvedon 

 (E.G.V.) ; Snareshrook. 



