PLATE XII. 



The figures in this Plate represent various forms of tlie Nodosarine, Globigerine, and Textularine types, and 



illustrate the structure of Fusuliiia. 



Fig. 



1.- 

 2.- 

 .'5.- 



7.- 

 H.- 



10.- 

 11.- 

 12.- 

 13. 

 14.- 

 15.- 

 16.- 

 17.- 

 18.- 

 19.- 

 20.- 

 21. 

 22.- 

 23. 



at. I 



-Lingulina costata. (After D'Orbigny.) 

 -Nodosaria hispida. (After D'Orbigny.) 

 -Cristellaria {Robulind) echinata. (After D'Or- 

 bigny.) 

 -Rimulina glabra. (After D'Orbigny.) 

 -GlanduUna lavigata. (After D'Orbigny.) 

 -Flabellina cordala. (After Reuss.) 

 -Orthocerina {Triplasia) 3Iiirchisoni. (After 



Reuss.) 

 -Orbulina universa ; at a, is seen a small portion 

 of its surface more highly magnified, showing its 

 tuberculated aspect ; and at b, a small portion 

 reduced in thickness, and more highly m.ag- 

 nifieil, to show its two sets of pores. 

 -Ovulites margaritifera ; a, a small portion en- 

 larged, showing the hexagonal areolation of its 

 surface, with a pore in each areola. 

 - Ovulites elongata. 

 -Globigerina helicina. 

 -Pullenia bulloides. 

 Spheeroidina austriaca. 

 -Animal of Textularia. 

 -Vulvulina gramen. (After D'Orbigny.) 

 -Chrysadilina gradata. (After D'Orbigny.) 

 -Cuneolina pavonia. (After D'Orbigny.) 

 -Bulimina Presli. (After Reuss.) 

 -Bulimina Buchiana. (After D'Orbigny.) 

 -Bulimina pynda. (After D'Orbigny.) 

 -Bulimina [Roberiina) arctica. (After D'Orbigny.) 

 -Bolivina costata. (After D'Orbigny.) 

 -Cassidulina [Ehrenbergind) serrata. (After 

 Reuss.) 



Cast of the chambers of a FusuUna of simple- 

 type, showing the alar prolongations extending 

 on either side nearly in straight lines from the 

 median segments. (After Ehrenberg.) 



Fig. 



(After D'Orbigny.) 



(After Schultze.) 



26.- 



28.— 



20. 



Transverse section of Fusulina, through its 

 centre, showing at a, a, the aperture con- 

 necting together the principal chambers c, c ; 

 and at b, b, the origins of the alar prolonga- 

 tions from the principal chambers. 



-Portion of the same section more enlarged, 

 showing an appearance of tubularity in the 

 outer walls of the chambers. 



Ideal view of Fusulina laid open in different 

 modes, to show its internal structure ; at a, is 

 seen the single fissured aperture situated in 

 the centre of the length of the shell (of which 

 nearly a half on the left hand has been re- 

 moved by a transverse section), communicating 

 with c, c, the principal chambers laid open 

 from the surface ; near the right hand ex- 

 tremity the septal plane e, e has been removed 

 to show the subdivision of the alar prolonga- 

 tions by the elongated secondary septa /, /, 

 which do not quite reach the spiral lamina, a 

 continuous gallery being left at b, b, by which 

 the chamberlets are connected ; at d the in- 

 terior has been laid open by the removal of 

 the septal plane, showing the necklace-like 

 form of the alar prolongations, and their alter- 

 nating arrangement. 



A portion of this last more enlarged, showing at 

 c, c, c , the cavities of the chamberlets, and at 

 b' , b, b the communicating jiassages ; a section 

 in the line a a will pass alternately through 

 the chamberlet c , and the gallery b' , giving 

 rise to the appearances shown in fig. 29. 



Transverse section taken near the extremity, 

 showing the elongation of the septa, and 

 their apparent divarication to give passage to 

 the narrow galleries U b' connecting the cham- 

 berlets, of the alar prolongations. 



