CARBONIFEROUS AGE. 11 



CARBONIFEROUS AGE. 



(CABBOJUFEROl'8 PERIOD.) 



PROTOZOA. 



CLASS KHIZOPODA. 

 ORDER Forauiiiiifcru. 



FAMILY GAMERIXID^E. 



Shell comparatively large and dense, discoid, lenticular, fusiform, cylin- 

 drical, oval, or subirlobose in outline; syiumctrically involute, or nircly 

 somewhat obliquely spiral. Last volution generally embracing all the 

 others, so as to present, in the typical genera, the form of an Ammonite or 

 .\uiitihix. Septa nearly always double, each chamber having its own 

 walls, which, without exception, diller from the rest of the shell in beiui;- 

 destitute of the ordinary tubular structure, so that the chambers are only 

 connected by the principal aperture, and a few large " orbuline" pores. 

 Canal system radiating between the double walls of the septa, generally 

 well developed and connected with the "intermediate skeleton," secreted 

 apparently for the consolidation of the entire structure. Aperture in the 

 typical forms a narrow fissure placed symmetrically between the outer 

 wall of the penultimate whorl, and the inner side of 'the last or outer 

 series of chambers ; sometimes partly closed by a shelly secretion so as 

 to leave only a series of pore-like openings; in Ampkittogfaa placed on 

 the under side of the spiral plane. 



In Dr. Carpenter's beautiful and elaborate Memoir on the Fora mini/' m, 1 pub- 

 IMird by the Ray Society, in 1862, the genera included in this family (there called 

 Xiniiiiitiliniila) arc the following, in part, however, under other generic names, 

 viz.: Camerina, (Atimwiti/i/es, Lamk.) Amphisteyhm, Oj H ,;-u/iini, Kl/>/tidium,= 

 (PolystotneUa, Lamk.) ffeterofitcgina, Cycloclypeus, Orbitotdes and Funilina. It in- 

 cludes the largest and most highly developed of the Foraminifera, as well as those 

 possessing the most densely constructed shells. The living examples are mainly 

 confined to the tropical and temperate seas, the larger types occurring in the tropics. 



In regard to some of the names here adopted, a word of explanation may not 

 be out of place. First it will be observed we use Bruguicrc's name 



To which we arc mainly indebted for the characters given in the above description. 



