A HISTORY OF ESSEX 



Helix bortensis, Mttll. 



Buliminus montanus (Drap.). ' Essex ' (Brit. 

 Mus.) 



etscurus (Mall.) 

 Cocblicopa lubrica (Mall.) 

 Azeca tridens (Pult.) 

 Ctectlianella acicula (Mall.) 

 Pupa cylindracea (Da C.) 



muscorum (Linn.) 

 Sphyradium edentulum (Drap.) 

 Vertigo anti-vertigo (Drap.) 



substriata (Jeff.) 



pygm* a (Drap.) 



moulinsiana (Dup.). Roydon 



pusilla, Mull. Bardfield (?) 

 Balea pervena (Linn.) 

 Clausilia laminata (Mont.) 



bidentata (Strom.) 

 Succinea putris (Linn.) 



elegans y Risso. 



b. BASOMMATOPHORA 

 Carychium minimum, Mall. 

 Melampus denticulatus (Mont.). River Colne, 



Wyvenhoe 

 Alexia myosotii (Drap.). Grays ; Purfleet ; 



Dovercourt 

 Leuconia bidentata (Mont.). Brightlingsea ; 



Dovercourt 



Ancylus ftuviatilis, Mall. 

 Velletia lacuitris (Linn.) 

 Limntea auricularia (Linn.) 



pereger (Mall.) 



palustris (Mull.) 



truncatula (Mall.) 



stagnalis (Linn.) 



glabra (Mall.). Woodford ; Barking Side ; 



Colchester 



Planorbis corneus (Linn.) 



albus, Mull. 



g/aber, Jeff. Carswell Pond ; Dagenham 



nautileus (Linn.) 



carinatus, Mall. 



marginatus, Drap. 



vortex (Linn.) 



spirorbis, Mall. 



contortus (Linn.) 



fontanus (Lightf.) 



lineatus (Walker) 

 Physa fontinalis (Linn.) 



hypnorum (Linn.) 



II. PROSOBRANCHIATA 



Paludestrina confusa (Frau.). Becton (probably 

 now extinct) 



jenkinsi (Smith). Becton ; Rainham ; 



Tilbury 



ventrosa (Mont.). Coldharbour Point to 

 Tilbury ; Thurrock Marsh ; between 

 Walton and Thorpe-le-Soken 



stagnalis (Bast.). Grays ; Tilbury ; Wy- 



venhoe ; Colchester 

 Bithynia tentaculata (Linn.) 



leachii (Shepp.) 

 V'mipara vivipara (Linn.) 



contecta (Millett). Old River Lea ; Col- 



chester ; River Stour 

 Valvata piscina/is (Mall.). 



cristata, Mttll. 



Assiminea grayana, Leach. Grays and other 

 spots along the Thames ; River Colne, 

 Colchester. (Becoming extinct) 



Pomatias elegans (Mull.). Felstead ; Coggles- 

 hall ; Saffron Walden ; Wicken Bon- 

 hunt ; Belchamp 



Neritina flwviatilii (Linn.). 



B. PELECYPODA 



Dreissensia polymorpha (Pall.). River Lea 

 Unto pictorum (Linn.) 



tumulus, Retz. 

 Anodonta cygneea (Linn.) 



Spharium rivicola (Leach). River Stort 



corneum (Linn.) 



male (Fir.). Woodford 



Spkterium lacustre (Mall.) 

 Pisidium amnicum (Mall.) 



pusillum (Gmel.) 



nitidum, Jenyns. Colchester 



fontinale (Drap.) 



milium (Held.). Lea Marshes 



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