202 KANSAS UNIVERSITY SCIENCE BULLETIN. 



RHIZOPODA. 



Pseudopodia of variable forms, blunt, sharp or anastomosing; naked, 

 or with a shell which is either homogeneous or made of plates, sand grains, 

 diatom shells, etc. 



All of the following forms belong to the suborder Thecamoebida of the 

 order Lobosa. 



DiFFLUGiA Leclere. 



Shell formed of foreign material, grains of sand, diatom shells, etc., 

 united by a chitinous connecting substance. 



Form spherical to pear-shaped, frequently with spine at the posterior 

 end. Mouth occasionally excentric. Body not completely filling the shell, 

 with finger-like pseudopodia. Nucleus and contractile vacuole variable. 



Difflngia reproduce by an extrusion of a portion of the cell mass and 

 by the formation of a new shell about the extruded portion, after which 

 the two individuals separate. 



Difflugia corona Wallich. Fig. 12. 



Difflugia globulosa Duj. Figs. 7, 8, 13, 14, 16, 17, 20, 21, 29, 30, 32. 



Difflugia lobosloma Leidy. Figs. 2, 4, 33. 



Difflugia pyriformi Perty. Figs. 1, 2, 5, 6, 9, 10, 19, 22, 28, 31. 



Difflugia arcula Leidy. Fig. 11. 



Difflugia coristricta Ehrenberg. Figs. 15, 23, 24. 



Difflugia acuminata Ehrenberg. Figs. 18, 26. 



Difflugia urceolata Carter. Figs. 25, 27. 



Difflugia corona Wallich. 



Shell spheroidal, composed of particles of sand, the fundus usually 

 spined. Mouth terminal, circular, with notched border. Is one of the 

 larger species of the genus. Distribution general, found usually with 

 algae. The small tooth-like processes bordering the mouth may vary 

 in number, but are usually more than ten. The number of spines also 

 varies, but seldom have less than four or five to an individual been ob- 

 served. Plate XXX; fig. 12. 

 Difflugia globulosa Dujardin. 



Shell more or less spheroidal in shape, composed usually of quartz 

 sand. Mouth large, terminal, seldom with a well-marked neck. One of the 

 smallest and rarest species of the genus. Fundus usually evenly rounded, 

 bearing no spines. Mouth is large, round and without lobes. The habitat 

 of this species is similar to that of other members of the genus. Plates 

 XXIX, XXX, XXXI, XXXII; figs. 7, 8, 13, 14, 16, 17, 20, 21, 29, 30, 32. 

 Difflugia lobosboma Leidy. .095 length. 



Shell small, oval, usually composed of fine sand grains. Mouth termi- 

 nal, small with 3 or 4 well marked lobes. Psd. as in other members of 

 the genus. Common in pond water and has wide distribution. Plates 

 XXIX, XXXII; figs. 2, 4, 33. 

 Difflugia pyriformis. 



Shell oval or pear-shaped, sometimes with a short neck and broadly 

 expanded fundus with or without spines, composed mainly of sand grains. 



