EXPLANATION OF THE PLATE. 



Fig. 1. A reversed specimen lent by Mr. Brockton Tomlin. 



Figs. 2 and 3. In these specimens the mouth is bent upwards and passes 

 over the spire. In Fig. 2 the spire is in the mouth. Fig. 3 

 shews another view of a specimen further grown. 



Fig. 4. In this specimen the tube of the whorl increases and decreases 

 in diameter alternately, thus having an undulating plane of the 

 surface. 



Fig. 5. The last whorl is nearly at right angles to the earlier ones. 



Fig. 6. The direction of the axis of the shell is much altered. 



Fig. 7. The last whorl is detached from the others. 



Fig. 8. The last whorl gapes away from the earlier ones, but returns to 

 the normal just before the mouth. 



Figs. 9, 10, and 11. These specimens show the varying height of the 

 spire. 



Fig. 12. This shell is from the mouth of the Fleet where the water is 

 salt, and is of much thicker substance. The other specimens 

 come from near Langton Herring, where the water is brackish 

 and weed is present. 



