TKITON. t 



smooth or nodulous ; the canal louy; or short ; the outer lij) 

 erenated or deutienlated within. 



Operculum ovate, its growth auiuilar either IVom a suh-api(^Tl 

 or submarginal nucleus. 



Whilst the lingual armature of 'Triton allies it chjsely with 

 Jktliwn^ etc., among the so-called taenioglossate molluslxs, the 

 affinities of the animal are on the whole closer, and those of tlu- 

 shell decidedly so, to Muricida?.* It may be considered a 

 connecting link between the two groups, but certainly cannot be 

 safely removed from the vicinity of the latter, to Avhich it is not 

 only allied by its operculum (which is entirely ditferent from that 

 of Bolium), Ijut so closely l»y the shell in some instances, that 

 the assignment of the generic position is quite arbitrary. 



The Tritons are distinctly tiopical in distribution, no species 

 inhabiting the colder seas. The species are niimerous and beau- 

 tiful, })resenting a great range of variation in size and color ; one 

 species being almost the largest of gasteropod mollusks, attaining 

 a lengtli of one and a half feet, Avhilst others, belonging to the 

 Epidromoid section, do not exceed a half inch in length. The 

 cancellated forms are chiefly East Indian, and are dredged in sand 

 in deep water; the West Coast of America group, covered with 

 a rough ejjidermis, is obtained in sandy mud at from six to thirty 

 fathoms' depth. A number of species have a w^orld-wide distri- 

 bution , which is doubtless due to their free-swimming or pelagic 

 larvae. These, unlike the Murices, but like the Purpurae.f are 

 very different at ttrst from tlie adult both in animal and shell. 

 undergoing a metamorphosis at a period subsequent to hatching. 



I adopt the well-known name Triton in preference to the pre- 

 viously given Tintonium of Cnvier, believing that the interests 

 of science are best conserved by keeping the nomenclature as 

 stable as possible. Triton has been used in other departments 

 of zoology, but so have many other generic names, which are 

 nevertheless accepted without cjuestion. The fact is, that prac- 

 tical common sense has quietly shelved the British Association 

 rule forbidding the use of a generic name in more than one 

 branch of zoology. In these days only the very few enjoying 



* See Vol. 2, Manual of C'ouchology, page 67. 

 t Vol. II, plate 8. 



