CHAPTER V 



ECONOMIC USE 



For the use of foraminifera in determining geologic correla- 

 tion, especially in checking well drillings, methods different from 

 those used for purely scientific study are necessary. Speed in 

 handling material is often one of the most important factors. 

 Anything that will allow of the greatest speed and at the same 

 time the greatest accuracy is essential, and other things may be 

 sacrificed to these. 



Avoidance of scientific names other than that of the genus 

 has been used by the writer in all his economic work. It has 

 been found sufficient to place a specimen in its proper genus, 

 then to give it a number with the formation character. Thus 

 Nodosaria- Tm-1 will stand in the work as a definite species of 

 Nodosaria from the Tertiary and the Miocene Monterey shale; 

 Nodosaria Cv-1 a particular species from the Cretaceous, Velasco 

 shale of Mexico. A "type specimen" is selected and mounted as 

 a permanent reference slide for each "species" or number. A 

 short description on a card catalog card is made and filed for 

 reference under its number and camera-lucida drawings in 

 different views made and filed. As Nodosaria Tm-2 is found, it 

 finds its proper place and is likewise permanently recorded. For 

 ease in reference, plates are built up of the figures so that all 

 numbered Nodosarias for instance are quickly seen on one plate. 

 No occasion arises for consulting published figures or the gen- 

 eral literature which, unless time and a large library are avail- 

 able, would probably result in a wrong specific name being given 

 to the specimen. The abbreviated form of letter and number 

 makes recording simple, makes columns in charts less difficult 

 to handle, and is a great time saver. It also places the species 

 in its general geologic position for future work. A worker can 

 mount, draw, and briefly describe many numbered f orjKts: wl)til^^ 



