NEOCENE STRATIGRAPHY. 329 



These strata, like the Atlantic Miocene, are character- 

 ized by many huge Pectens, large Areas, and other forms 

 which have no representatives in the present waters of 

 the coast. Thus, there is on the coast of California one 

 very small species of Area, found at San Diego. In 

 these strata we find great numbers of several species of 

 Area, some of which are over four inches broad. The 

 most common of these, the A7'ca microdonta Conrad, will 

 fit the figure and description of Area arata Say of the 

 Maryland Miocene just as well as it does Conrad's figure 

 and description of the west coast species. The presence 

 of the large Pectens, six or seven inches across, gives the 

 fauna a strong resemblance to the Atlantic Miocene of 

 Virginia and Maryland. Aside from the above localities, 

 these Pectens have been previously quoted only from 

 strata generally acknowledged to be Miocene. The 

 Crefidiila grandis Midd. is another form about four times 

 as large as any of its living representatives. The Cardi- 

 um meekianuTn Gabb, Saxidomiis gtbbosus Gabb, Mactra 

 (not Venus) -pajaroensis Con. and the Echinii, Scutella 

 Gibbsi Rem. and S . mtei'lineata Stimp. are among those 

 which have no living representatives. A number of oth- 

 ers are only known now living in distant seas. In sev- 

 eral cases it is found that certain characteristics of a spe- 

 cies have changed. 



We have seen that there is good evidence that the beds 

 just north of Mussel Rock and those between Point Mon- 

 tara and Pillar Point are the same as those further south 

 at Purissima, etc. The fauna at Point Pillar though small 

 did not give a single form living in the present fauna 

 there, though the lower beds toward Point Montara did; 

 thus seeming to support the structural evidence. 



The fauna, while closely related to living faunas, as 

 shown by the percentages given above, is found to have 



