389 



CHITONIDiE. 



" It seems to me,"" writes Milne Edwards in the short 

 bnt valuable paper to which we have just referred, " that 

 the animal kingdom, taken as a whole, cannot be com- 

 pared with a well-regulated army, where each brigade, 

 each regiment, and each company, has well-defined limits, 

 and where every soldier has his fixed place under the flag 

 of his corps ; to give a just notion of it, it might better 

 be compared to the stellary system, where a multitude 

 of stars are disseminated at unequal distances, and form, 

 from distance to distance, by their presence in great 

 number within limited spaces, groups more or less remark- 

 able, about which we see other stars, isolated as it were 

 in the heavens, and not making part of any great system. 

 The analogues of these constellations, in zoology, constitute 

 classes and orders, and in the voids between them we 

 often find some species which differ as much from all 

 these groups as they differ among themselves, but which, 

 being few in number, are not permitted to assume the 

 same rank in our classifications as types do which are 

 rich in species." 



These sentiments are offered as illustrative of the family 

 before us, which is considered by Milne Edwards as even 

 doubtfully belonging to the mollusca, and at nearest, as a 

 satellite group of Gasteropoda having relations to the Pro- 

 sohranchiaia. The Chitons have, indeed, been zoological 

 l>uzzles, though regarded by the majority of malacologists 



