CHAPTER VIII 



CLASSIFICATION 



Numerous attempts at classification of the foraminifera have 

 been made from the time of the appearance of d'Orbigny's 

 classic Tableau Methodique published in 1826. Nearly all the 

 classifications since d'Orbigny's time have been based upon the 

 resemblance in form of the adult test. The classification adopted 

 in Brady's Challenger Report of 1884 with its ten families has 

 been the one in most general use since that date. It hov^ever 

 places together forms which are now known to have very dif- 

 ferent beginnings, although their adult forms may have certain 

 points in common. The classification adopted here is that given 

 in outline about a year ago, Cushman, An Outline of a Reclassifi- 

 cation of the Foraminifera, (Contrib. Cushman Lab. Foram. 

 Res., vol. 3, pt. 1, 1927, pp. 1-105, pis. 1-21.) In that outline an 

 attempt was made to bring together the best thought developed 

 on the relationships of the foraminifera since the publication of 

 Brady's Monograph in 1884. Since that date, much has been 

 learned in regard to the development of foraminifera, and many 

 new genera have been erected. 



An ideal classification should be based upon the known 

 phylogeny of a group as shown by the fossil record, and coupled 

 with the ontogeny of the individual as shown in its complete 

 development together with what may be learned of the 

 morphology and physiology of the group. 



In the foraminifera as has been mentioned, there are at least 

 two distinct forms, one the result of the fusion of gametes after 

 mitotic division, the microspheric form, the other the result of 

 simple division, themegalosphericform. Inthefirstof theseforms 

 the early stages are more nearly complete while in the second and 

 early stages may be skipped and the adult characters taken on 

 almost at once. It is very evident that any classification must 

 be based upon the relationships shown in this microspheric form 



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