86 HELICID.E. 



subglobular shell, which is partly covered by 

 the back edge of the shield, and a tongue-like 

 process of the mantle on the 

 right side. Jaw strong, lunate, 

 smooth, with a strong central 

 projection ; tongue broad ; teeth 

 numerous, Avith a single pro- 

 longed apex to the edge tooth, like Limax. 

 Shell imperforated ; spire depressed, of only a 

 few whorls ; mouth large, rounded, lunate ; 

 peristome thin. 

 This genus is intermediate in form between a 

 slug and a snail, having; the shield-like mantle of the 

 one, and the globular external shell of the other 

 genus. The shells are very like the Zonites in their 

 appearance, but have a much smaller and more de- 

 pressed spire, more rapidly enlarging whorls, and 

 a much larger mouth ; but they are best known by 

 their axis being imperforated. 



Nilson kept some specimens, which he had caught 

 at the end of January, in a bell glass ; and on the 

 19th of February he observed some eggs placed 

 among the putrescent leaves. The eggs were oval, 

 globose, white, subpellucid, with a central opaque 

 spot, and placed in little tufts, consisting of eight or 

 nine eggs. In the beginning of March the opaque 

 spot was not increased in size, but showed signs of 

 slow movement; and on the 21st or 22nd of March 

 the animals were excluded. He thought, when he 

 observed them with the microscope, that the animal 

 bored its way through the egg-shell, foi'ming a hole 

 out of which first the head, and then the foot, was 



