TRITO.N^. 113 



ridge_, with all its varieties of embellishment^ as highly 

 finished and harmonious in its hues, as might be antici- 

 pated from a mature artist. Spines and laminee, or tubercles, 

 are secreted by certain thread-like processes along the edge 

 of the mantle, previous, it is assumed, to a season of rest ; 

 or in other words, the animal is able to suspend at will the 

 function of liis calcifjang organ, thus forming different 

 intervals, in a manner analogous to that which induces the 

 formation of claws in the mature Pferocera. 



Triton shells are more solid, and yet simple in their 

 structure, than such as pertain to the Micrex or Eanella. 

 They have neither fronds nor spines, nor yet ramified 

 branches like the Murex : the rude manner in which their 

 whorls are convoluted seems to indicate that the molluscous 

 occupant, though possessing abundant masonic powers, is 

 of somewhat sluggish disposition. The epidermis is often 

 remarkably thick and hairy, occasionally even varied with 

 bristles in small tufts; and the apex, in numerous in- 

 stances, is formed apparently of a horny substance, thinly 

 plated with shelly matter. Hence it happens not unfre- 

 quently, that the calcareous plating, being broken ofp, 

 exposes the horny cast beneath. Another peculiarity is 

 obvious in the columella being adorned with a bright coat 



