Genus Cypr(Ba. 209 



Briefly, then, it is evident that as a plant, insect, or shell 

 may be considered a perfect representative of its species only 

 so long as all the distinguishing traits and combinations of 

 character exemplified in the original type are present, so it 

 becomes a variety^ when, owing to some local or other cause, 

 one or more of these typical characteristics disappear, and 

 change it to that extent. 



In the genus under discussion, too much reliance must 

 not be placed on either forvi^ colour^ texture^ sice, pattern, 

 nor (always) dentition ; but three or four of these points 

 will be found present in every variety, while, crowning all, 

 there is nearly always an indefinable and intuitive per- 

 ception that will enable a specialist to recognise and relegate 

 to its proper position with confidence, any individual he 

 may be asked to decide upon. 



{a) Form. — The chief variations are either undue pro- 

 longation, as in some specimens from New Caledonia, a 

 more effuse growth than is ordinary, or a contracted and 

 stunted form, generally thickened laterally. Monstrosities 

 occur in many of the species. 



iU) Colotir. — Colour varieties affect some species far 

 more than others ; they run into each other very closely, 

 e.g., C. tigris vars. : but certain stand out, constantly recur, 

 and are always recognisable. The Sandwich Isles and the 

 Island of JMatiritins each possess races of Cowries, of 

 various species, in which the whole shell has become semi- 

 pellucid, and of a golden yellow or straw coloured hue, 

 almost free from markings. These probably come from 

 deep water, and, in a few species, unicolorous green varieties 

 also occur. ■ • 



{c) Texture. — Varieties from deep water are sometimes 

 thinner than usual, and in certain forms, e.g., G. carneola, 

 the lateral thickening spoken of under {a) gives a greater 

 ponderosity to the shell. 



id') Size. — Certain species, as C. lynx, carneola, etc., often 

 attain unusual size, three or more inches in length, when 



