3394 Mollusks. 



ter becomes free of weeds and clear, and the whole tribe of Planorbis 

 are left behind. From Broadgate, all through the Highfield House 

 estate, the dike only contains Limneus pereger, and, in one or two 

 places, Ancylus fluviatilis, and on the moist mud on its banks, Succi- 

 nea Pfeifferi and Limneus truncatulus. The Musco-Sic brook branch- 

 es out from it at Broadgate, and joins it again at the east extremity of 

 the Highfield House estate ; this brook at first contains Planorbis 

 marginatus, P. vortex, P. carinatus, P. corneus, Bithinia tentaculata 

 (very large), Valvata piscinalis, Limneus pereger, Cyclas cornea, Pisi- 

 dium pulchellum, and Limneus auricularius. 



A very clear brook at Attenborough, with Algae growing in it, con- 

 tains Planorbis corneus, P. carinatus, P. marginatus, P. vortex, P. 

 spirorbis, Ancylus fluviatilis, Bithinia tentaculata, Limneus pereger, 

 L. auricularius, L. stagnalis, and Physa acuta. 



A similar brook at Lenton, near the railway, contains Planorbis 

 corneus, P. vortex, P. spirorbis, P. carinatus, Limneus stagnalis, L. 

 auricularius, L. pereger, Physa acuta, P. fontinalis, Valvata piscinalis, 

 Cyclas cornea, and Bithinia tentaculata. 



A small ditch, some fifty yards from the last-named locality, con- 

 tains Bithinia ventricosa, B. tentaculata, Limneus truncatulus, L. per- 

 eger, Valletia lacustris, Planorbis vortex, P. spirorbis, P. carinatus, 

 and P. contortus. 



The lake at Highfield House contains Anodon cygneus, A. cel- 

 lensis, A. anatinus, a var. of A. anatinus, Unio pictorum, U. tumidus, 

 Dreissena polymorpha (very large), Planorbis nitidus, P. imbricatus, 

 and Limneus pereger. 



The river Soar at Thrumpton contains Cyclas rivicola, C. cornea, 

 Unio pictorum, Dreissena polymorpha, Anodon cygneus, A. anatinus, 

 Limneus pereger, L. stagnalis, and Paludina achatina. 



The river Trent near Beeston contains Pisidium pulchellum, Ano- 

 don anatinus, A. avonensis, A. cygneus, Cyclas cornea, C. rivicola, 

 Bithinia tentaculata, Limneus pereger, L. stagnalis, Physa acuta, 

 Neritina fluviatilis, Planorbis carinatus, P. vortex, P. spirorbis, P. 

 albus, Unio pictorum, U. tumidus, U. ovalis, Limneus palustris, Val- 

 vata piscinalis, and Dreissena polymorpha. 



Under the Seven Arches in Nottingham Meadows are Planorbis 

 carinatus, P. spirorbis, P. vortex, Bithynia ventricosa, B. tentaculata, 

 Valletia lacustris, Cyclas cornea, and Limneus pereger. 



In the river Lean at Bulwell there are Valvata piscinalis, V. cris- 

 tata, Planorbis carinatus, P. contortus, P. vortex, Bithinia tentaculata, 

 Limneus pereger, Anodon cellensis, and Ancylus fluviatilis. 



