102 THE MICROSCOPE. July 



Geological Distribution of the Foramenifera. 



By ARTHUR M. EDWARDS, M. D., 

 NEWAKK, N. J. 



Foramenifera are widely distributed in geography, 

 being found almost everywhere. They are also widely dis- 

 tributed geologically being found in the oldest rocks and 

 so up to the most recent. And as they are seeming thus 

 universal it is a wonder that they have not claimed and 

 enjoyed a larger part of the labors of the naturalist. It 

 is my wish to endeavor to clear up what is known of them 

 here. 



The designation Foramenifera was given by D'Ortigny 

 in 1825 to an order of animals forming minute calcareous 

 shells. They are for the most part many chambered, and 

 often bearing a strong resemblance in form to those of 

 Nautilus, Orthoceros, and other chambered shells or 

 Cephatopods. He supposed Cepholopoda foramenifera 

 to be distinguished from the real Cephalapada sipuncu- 

 lifero by the want of a "siphon" which passes from cham- 

 ber to ciiamber in the latter, and its replacement in the for- 

 mer by mere "Foramana," at the dividing septa. This was 

 where the shells alone wpre studied without tlie animals, 

 now that the animals are studied it is found that they 

 must be placed low down in the animal kingdom, in fact 

 at the lowest where the Protista come in. For amcjeba, 

 the lowest form of the animal, is related closely to the 

 Foramenifera. It was the paper upon living For- 

 amenifera by Dujardin, in 1836, tliat attention was first 

 drawn to the existence of a type of animals more simple 

 than any previously known, their bodies consist- 

 ing entirely of an apparently homogeneous semi-fluid 

 substance, to which he gave the name of "sarcode;" and 

 this substance projecting itself through apertures of the 

 shell into indeterminate ramifying extensions (which he 

 termed pseudopodia) in the general mass of the body. 



