2 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



Many of the coiled forms were early described as species of Nautilus, 

 and it was not until 1835 when Dujardin recognized the relationship 

 of the group to the rhizopods that their systematic position was 

 finally settled. 



The classification of the group has been very differently treated by 

 later writers. Led by W. B. Carpenter, there grew up what may be 

 termed the English school of workers on this group. Four names 

 stand out prominently, those of W. B. Carpenter, W. K. Parker, 

 T. Rupert Jones, and H. B. Brady. The first three especially worked 

 on the basis of no sharp lines of demarcation between species or 

 genera or even between larger groups. The group was supposed to 

 be very variable, in fact so much so that genera were recognized as 

 tentative only and not really distinct. Brady, while holding many 

 of the same views, nevertheless described many new genera and 

 species, drew the lines more closely for the genera, and worked out a 

 fairly good classification of the whole group. He was, however, led 

 by the same plea of variation to unite recent forms with often dis- 

 similar fossil species, on the basis of similar characters in one part 

 or another, even while the whole test was often very different. With 

 the large series obtained in the present work it is possible to show, not 

 only that variation is not so great as was thought by the English 

 school, but what was by them called variation is not variation 

 at all but definite stages in the development of the test, which often 

 at different stages has very different characters. In the light of the 

 present knowledge of the life history and the microspheric and 

 megalospheric forms these supposed variations take on a decidedly 

 different aspect and become of use in the separation of genera rather 

 than in uniting them. While these points are not so clearly brought 

 out in the arenaceous forms described in the first part of the present 

 work, they are well seen in certain of the other families. 



Schlumberger, in distinction from the English school, had very 

 different ideas as to the variation and the classification of various 

 forms. He argued that with other groups the identity of fossil and 

 living forms becomes small in the Eocene, and in the Cretaceous is 

 hardly known, yet the workers of the English school had no difficul- 

 ties in uniting recent species with even Jurassic or still older forms. 

 Schlumberger argued that when such similarity existed it was simply 

 a lack of characters, and that the two forms were potentially distinct. 



Distribution has been thought to be of little account in the group, 

 either by regions or by depth. Certain species, for instance, are 

 recorded by Brady as from 18 to 3,950 fathoms, and with a world- 

 wide distribution. With material from scattered stations and a 

 worker attempting to explain all differences on the basis of varia- 

 tion such views may be held, but with larger series from many sta- 

 tions, such as have been available in the present work, the material has 



