C ONCHOLOGY. 



Genus— TRIPLEX. Species— TRIPLEX FOLI- 



ATUS. 



Character. — Shell spiral univalve ; the body, spire, and 

 beak invested with three septae or membranaceous 

 divisions, formed into tubercles and spines ; the 

 mouth round and carunculated, colour varying 

 from a reddish brown to a pale rose colour. 



IT has been very justly remarked by different Con- 

 chologists, that the external form of Sea Shells (and indeed 

 of the Land Shells also) affords the only certain criterion by 

 which each genus may be distinguished. For of the shape 

 and constitution of the animal itself we must remain for ever 

 ignorant, as the only state in which the greatest number are 

 obtained, is when they are empty and deserted by the ani- 

 mal, washed up by the force of tempests or currents of the 

 sea. The triplex genus of Shells are remarkable for their 

 triangulated form, which is occasioned by three thick di- 

 visions placed lengthwise on the outside of the Shell, and 

 which form its chief ornament. Other Shells, which in 

 many respects have a resemblance to it, are distinguished in 

 a similar way : the Monoplex has one fold on its body ; the 

 liiplex two folds ; the Hexaplex six folds, and so on with 

 the following species, until we arrive at the greatest num- 

 ber, the Polyplex, in which the folds are very numerous, 

 but the number not defined, and indeed of these latter but 

 few have been discovered, and those only in the Southern 

 Ocean and islands lately discovered by the investigations 

 of Captain Cooke and other navigators. 



Amongst the most agreeable and pleasing forms of 

 Shells, which the extensive regions of the East Indies have 



