6 PROTOZOA. 



Make a careful drawing of an Amceba. 



Amoebae of various kinds represent in many respects the 

 simplest type of protozoan, and are therefore placed in the first 

 class of these animals, the Sarcodina. The individuals of this 

 class all possess pseudopodia, but many are quite unlike those 

 of Amceba. Look over the figures of various Rhizopoda. 



If time and material permit, study Amoeba verrucosa, Arcella, 

 and Difflugia, and compare them with Amceba proteus. Do you 

 understand how the shells of the last two genera are made, 

 and of what service they are? 



Drawings of these forms are desirable. 



Calkins: Genera and Species of Amoeba. Trans. Fifteenth International 



Congress on Hygiene, 1912. The Fertilization of A. proteus. Biol. 



Bui., 13, 1907. 

 Bellinger : Locomotion of Amceba and Allied Forms. Jour. Ex. Zool., 3, 



1906. 



Metcalf : Amceba Studies. Jour. Ex. Zool., 9, 1910. 

 Popoff: Ueber den Entwicklungs cyclus von A. minuta. Arch. f. Protis- 



tenk., 22, 1911. 



THE FORAMINIFERA. 



With very few exceptions Foraminifera are marine and pro- 

 vided with shells. Empty shells from deep-sea dredgings or from 

 the sand beaches of such islands as the Bermudas may be had 

 for study. Examine them with a low power by reflected light. 



1. Carefully examine various shells, compare them with each 

 other and with figures. Notice the great variety in size and 

 shape and determine how the chambers must have been added 

 during growth. 



2. Observe a single opening in a shell, and determine whether 

 the general surface has any finer perforations. Be sure to under- 

 stand the relation of the live animal to the shell. 



Make drawings of several types of shells. 



Farmer: Foraminifera, pp. 133-139, Lankester's Treatise. 

 Flint: Recent Foraminifera. Rep. U. S. Nat. Mus., 1897. 



ACTINOSPHAERIUM OR ACTINOPHRYS. 



Find, as usual, with the low power, and increase the magni- 

 fication as occasion demands. 



1. Note the many fine radiating pseudopodia. These are quite 



