54 CATALOGUE OF SHELLS. 
17. N. Cryptomphalos B. W. Theobald Junr. 
Tenasserim [?,——. 
On stones in rapids above the influence of the tide. 
18. N. Mertoniana. E. L. Layard 
Ceylon. Philippines. 
eee an as a Von de Busch. 
a. Mexico. 
b. Alabama. 
c. Tampio. To7P'<? 3 
These specimens (b.) were labelled by some mistake N. Fluviatilis. 
20. N. Fluviatilis Lin. Mr. Strickland. 
Britain. 
ONemNs 
West Indies. 
A. very variable shell as to markings closely allied to N, 
Mertoniana. 
22. N. spe W. Theobald. 
Salween R. 
Much like N. Depressa (var). but of its history I remember 
nothing. 
Gen. NAVICELLA Lam: 
1. N. Ccerulescens. Reeve. 
NN. Tessalata apud Benson. 
N. Orientalis Reeve. 
a. b. Calcutta. 
