FORAMINIFERA 



^?> 



Despite the apparent iiiiifornnty of tlie protoplasmic body in 

 this group, tlie shell is infinitely varied in form. As Carpenter 



g.Planorbulina 



ll.Nummuiires 



Fig. 13. — Shells of Foraminifera. In 3, 4, ami 5, a shows tlie siirlace view, and h a 

 section ; 8a is a diagram of a coiled cell without supplemental skeleton ; 86 of a 

 similar form with supplemental skeleton {s.sk) ; and 10 of a form with overlapjniig 

 whorls ; in 11« half the shell is .shown in horizontal section ; 6 is a vertical .section ; 

 a, aperture of tlie shell ; 1-15, successive chambers. 1 beins,' .always the oldest or 

 initial chamber. (From Parker and Haswcll, after other authors.) 



wriies, in reference to the Arenacea, " There is nothing more 

 wonderful in nature than the building up of these elaborate and 

 symmetrical structures l)y mere jelly-specks, presenting no traces 



