LEFTON. 81 



and the superabundant filamentous matter is similarly dis- 

 charged. 



The L. squamosum is a lively creature, but this, not one- 

 third of the size, is far more active, creeping up a glass as 

 easily as a Gasteropod ; but the posterior portion of the foot 

 is not expanded; perhaps in freedom it is deployed on the 

 march ; in confinement both shell and foot are carried laterally. 

 The liver is light green, united to a flake-white ovarium, now, 

 in June, full of ova. Transverse length J, vertical y 1 ^, dia- 

 meter -Jj of an inch. It would appear that this species in 

 every essential is identical with the L. squamosum, and it 

 settles the position of the yet undiscovered L. convexum. This 

 is the first record of this rare animal that has appeared. 



Exmouth, June 20, 1852. 



I have this day the pleasure to state, that the problem is 

 solved as to the identity or distinctness of the Lepton nitidum 

 and L. conveocum by the capture of a live specimen of the 

 latter, having the shell sculptured with the rough and intensely 

 marked characteristic punctures of that species. On putting 

 the animal into water it instantly deployed its organs ; and for 

 their description I have only to refer to the preceding account 

 of the L. nitidum, which in future will take the appellation of 

 a variety of its old associate. The two are so identical, that 

 after ten days' examination I can make no alteration in the 

 minutes, except the having seen the animal march on the disk 

 of the foot, more than once, with the shell in a vertical posi- 

 tion ; it has all the same habitudes as the L. squamosum, and 

 of course differs in no respect from its smoother variety, the 

 late L. nitidum. It is now alive, and probably by changing 

 the water daily it will live as long or longer than the L. squa- 

 mosum mentioned above. It is therefore evident that the 

 punctures of this species are very variable, ranging from the 

 most minute granules that scarcely interrupt its smoothness to 

 the coarsest sculpture. 



As the specific appellation of nitidum is obviously improper, 

 the more significant one of convexum ought now to be adopted. 



Since the above was written I have taken two examples, one 

 this morning (July 18), of the smoothest variety of the ' con- 



G 



