24 AN INTRODUCTION TO THE STUDY OF FOSSILS 



the prehistoric shell heaps in America, it is evident that it was 

 introduced from Europe about the middle of the nineteenth 

 century, for it was recorded from the Gulf of St. Lawrence in 

 1850. Thence it slowly spread southward along the coast, 

 probably by the transport of its larvae by the southward-flowing 

 Greenland current. In 1870 a few were noted on the Maine 

 coast; in 1872 it was found at Salem, in 1880 at New Haven, 

 and in 1891 as far south as Delaware Bay. In each locality 

 where observed it had become the most abundant gastropod 

 within two or three years after its first appearance. On the 

 New England coast it covers the rocks and seaweed between 

 tide limits. 



Naming of organisms. — In early times, only variable com- 

 mon names or a single technical name was applied to a species 

 of animal or plant; more often the name was long and descrip- 

 tive. This procedure was first changed by the great Swedish 

 naturalist, Linnaeus (or Linne), who introduced the binomial, 

 or two-name, method. His great work ('' Systema Naturae'') 

 was published in 1735 ; this was in Latin, the scientific language 

 of Europe at that time, hence all his technical names have Latin 

 or Greek endings. This use of Latin and Greek was found so 

 satisfactory, since the same names could be used by all nation- 

 alities and languages, that it now governs the naming of fossils 

 the world over. The generic name is usually taken from the 

 Greek and the specific name from the Latin language. As a 

 result the technical name of an organism, fossil or living, is the 

 same whether used in English, German, Russian, or Japanese 

 works. 



Before Linnaeus, the single technical name was often modi- 

 fied by a descriptive phrase ; for example, one of the lady bugs 

 was called the Coccinella with the seven black spots ; this 

 Linnaeus called Coccinella septem- punctata. The first of the 

 two names is that of the genus and represents the broader 

 relationship, the second is that of the species and includes all 

 individuals which are almost exactlv similar; this likewise 



