T N T H I) r C T ION. 



«;i:NKnAf. kkmakks on juk study of >a'ji kai. iiis'ior.v. 



Tin: Mollusca, classed by Ctivicr as the second of the ibtir 

 t,aeat classes into which he divided the Animal Kingdom, have 

 occupied tlic attention- of the greatest naturalists for more 

 than two thousand years. The IS'aulilus, known as ArgonmUa 

 avgo, Linn, was described by Aristotle, who represented it as 

 using its arms for sails and drifting before the wind. Aristotle 

 was the founder of the study of Xatural History in ancient 

 times. I have before nu; a Avork called the " History of Ani- 

 mals," written by him. Tliis work embraces all the know- 

 ledge of that distant age on this subject. Aristotle was 

 acquainted with genera and specties. He divided all animalu 

 into tAvo classes: those Avith blood and those without blood. 

 However, he placed in the latter class those animals Avhose 

 blood is colorless, Avhereas all bloods are not red as avc now 

 know. Pliny folloAved Aristotle. These two men were the 

 great lights of ancient times in Natural History. From that 

 period Ave pass over the dark ages and come doAvn to the six- 

 teenth century before Ave find the study resumed and once 

 more engaging the attention of naturalists. But as might be 

 e.vpected the results Avere very small, owing to the Avant of 

 system, difficulties of communication, and the different view.s 

 of investigators! And it Avas not until the eighteenth century 

 that Ave behold a new character and impetus given to the 

 ))ursuit of the science by the labors of Linnauis. Ainong other 

 things, we are indebted to him for our system of nomenclature. 

 I'rior to that time every naturalist had used such language 

 and terms as pleased him. A matter that caused much con- 



