MR. ARTHUR MAYFIELD ON THE MOLLUSCA OF NORFOLK. 189 
Pisidium fontin ale (Drap.), var. pulchella, Jenyns. In a ditch 
at Colney. 
*P. nitidum, Jen. In a ditch near Thetford. 
MAEINE. 
Modiolaria discors (L.). Common in sea-weed; Yarmouth, 
Cromer, Palling. 
Dkntalium entalis, L. In drift, Wells. 
Chiton oinereus, L. Wells Harbour. 
C. maroinatus, L. Sheringham and Cromer. 
Helcion pellucidum (L.) In drift, Wells. 
Trociius magus, L. Wells, lleacham. 
„ var. conica, Marshall. A single specimen of this 
rare variety (now in the possession of Mr. Marshall 
of Torquay) was picked up from drift at lleacham. 
T. umbilicatus (Mont.). Yarmouth, Cromer, Hunstanton, Wells. 
T. striatus, L. Wells. 
Lacuna divaricata, Fabr. In drift, Yarmouth. 
,, var. guacilior, Mete. One specimen, Yarmouth. 
L. i’allidula (Da C.). Yarmouth. 
Littorina nerltoides (L). Breydon Water. 
Kissoa parva (Da C.). A few specimens of the typical form in 
drift at Yarmouth. 
Hydrobia ventrosa, Mont. Plentiful in a ditch near Breydon. 
„ var. pellucida, Jeff. Breydon. 
Odostomia unidentata (Mont.). In drift, Wells. 
Skenea planorbis, Fabr. Breydon. 
Aporrhais pes-pelecani (L.). One water-worn shell in drift, 
Wells. 
Cerithium reticulatum, Da C. Wells. 
