16 * 
NOMENCLATURE, 
bilahiata. Bilabiate; constructed with both an 
internal and external lip ; in opposition to 
those shells which are destitute of the in- 
terior one. 
dehiscens. Gaping ; the lower part of the lip 
being distended. 
coarctata. Coarc tate ; contracted, straight : op- 
posed to effuse. 
effusa. Effuse; having the lips separated by a 
sinus or gutter, so that if the shell were 
filled with water it would flow out at the 
back part. 
rejiexa. Reflex ; having the fore part of the lip 
reflected towards the lowest whorl. 
repanda. Spreading ; having broad open lips. 
resupinata. Resupinate; turned upwards. , 
transmrsa. Transverse; situated in a plane pa- 
rallel to the inclination of the spiral line of 
the whorls; in the direction of that line. 
dentata. Dentate; furnished with teeth. 
Apex. Apex, Tip ; summit of the spire. 
decollatus. Decollate ; apparently mutilated, 
having the spire, or the upper part of it, 
horizontally cut off. 
