100 DESiEEDrELE. 



Micrasterias rotata, (Grev.) 



Durdhain Down Reservoir. 



Micrasterias truncata, (Corda) 



Bedminster; Asliton. 



Pediastrum ellipticum, (Ehr.) 



Stapleton Quarry. 



Penium Brebissonii, (Menegh.) 



Horfield ; Bedminster ; Chelvey ; Damory Bridge ; 

 Duchess' Pond. 



Penium digitus, (Ehr.) 



Avonmouth ; Stapleton ; Bedminster ; Chelvey ; 

 Bitton. 



Penium margaritaceum, (Ehr.) 



Ashley Vale : Horfield ; Leigh ; Stapleton. 

 Penium ? 



This specimen was found in the Reservoir, Durd- 

 ham Down. It had rounded ends, but without 

 markings^ probably an empty frond. 



Scenedesmus acutus, (Meyen) 

 Hanham. 



Scenedesmus dimorphus, (Turp.) 



Stapleton ; Xailsea. 



Scenedesmus obliquus, (Turp.) 



Stoke Bishop ; Ashton. 



Scenedesmus obtusus, (Meyen) 



Leigh; Stapleton; Horfield; Ashley Yale; Hanham. 



Scenedesmus quadricauda, (Turp.) 



Stapleton; Bedminster; Reservoirs at Barrow and 

 Durdham Down; Shirehampton. 



Sphoerozisma excavatum, (Ralfs) 

 Bedminster. 



