150 



General Biology 



chambers connected by openings (foramina), and are composed of cal- 

 cium carbonate. When these shells sink to the sea bottom, they become 

 Globigerina ooze, which solidifies, forming gray chalk. 



Fig. 65. 



A. to H. Isolated Nucleus of Thalassicola nucleata Hux. (After Verworn.) 



A. to D. Regenerative changes. 



E. to H. Degenerative changes. 



I. Actinomonas Pusilla (Kent) n, nucleus; /, flagellum; p, pseudopodia. 



14. The Mastigophora ( ) may easily be dis- 



tinguished from other Protozoa by the presence of one or more flagella. 

 Four orders are usually recognized: (1) Flagellata, 

 (2) Choanaflagellata, (3) Dinoflagellata, (4) Cysto- 

 flagellata. 



15. Order 1. Flagellata ( ) 



Mastigophora with one or more flagella at the an- 

 terior end of the body. 



Examples : Euglena, Mastigamoeba, Chilomo- 

 nas, Uroglena, Volvox. (Fig. 67.) 



Mastigamoeba ( ) is of 



Proto lasm 6 o'f Giobi s P ec i a l interest, since it appears to combine the dis- 

 gerina, after the shell has tinguishing characteristics of both the Rhizopoda 



been dissolved. n, nu- , , , . , . M . . .. 



cieus. (After Hertwig.) and Mastigophora ; that is, it possesses pseudopodia 



Fig. 67. 



A. Uroglena americana, Calkins, a sphareoid colony. 



B. Mastigamoeba as per a. (After Schultze.) 



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