XXxlil. 
Fissurellide. 
Fissurella, Brag., 1789. 
(Type F. nimbosa, an uncertain species, but certainly of this group.) 
F. greea, L. 
Emarginula, Zam., 1801. 
(type) E. fissura, Z. 
E. rosea, Bell. 
Puncturella, Lowe, 1827. 
(type) P. noachina, L. 
Acmeeidee. 
Acmeea, Eschscholtz. 
(type A. mitra, Esch.) 
A. virginea, Mill. 
A. testudinalis, Mil. 
Lepetide. 
Lepeta, Gray, 1847. 
(type) L. cxeea, AilL. 
Pilidium, Forbes, 1849. 
(type) P. fulvum, J/ii7. 
Propilidium, Forbes and Hanley, 1849. 
(type) P. ancyloide, Forbes. 
Patellidee. 
Patella, Z. 
(typical example) P. vulgata, L. 
Patina, (Leach) Gray, 1847. 
(type PB. cerulea, Mont., non L. = P. 
pellucidum, ZL.) 
P. pellucidum, L. 
The type species of Helcion, Montfort, is pectinata, Born, and therefore 
the name can hardly be used for our British shell. 
