76 ILLINOIS BIOLOGICAL MONOGRAPHS [286 



merite is overbalanced and drops to one side. Immediately thereupon 

 an outpushing of protoplasm on the other side either restores the nor- 

 mal condition or causes a nodding to the opposite side. This movement 

 may continue with surprising rapidity and extend over a long period of 

 time. The deutomerite above its median constriction is very motile, but 

 the portion below is never involved in violent contortions. 



This species is similar in general outline to Stenophora nematoides 

 Leger and Duboscq (1903a:335-7). Both have the peculiar and hitherto 

 unique constriction at the middle of the deutomerite. They differ in 

 the shape of the protomerite, which in Leger and Duboscq 's species is 

 much longer than wide ; in the shape of the nucleus, which in S. nema- 

 toides is elongate ovoidal and in S. diplocorpa is spherical; and in the 

 character of movement. I have in no case observed the nematoid shape 

 which is assumed by 8. nematoides and is due to the elongation of the 

 body and the entire disappearance of the constriction. Motion in 8. dip- 

 locorpa is confined chiefly to regions above the constriction and the lat- 

 ter never entirely disappears. 



A table of measurements follows, in which all dimensions are given 

 in microns : 



Total length of body 297 325 262 335 359 



Length of protomerite 19 20 12 15 14 



Length of deutomerite 278 305 250 320 345 



Width of protomerite _........ 20 20 20 15 15 



Width of deutomerite 45 57 40 45 45 



Ratio 



length protom.: total length 1:16 1:16 1:22 1:22 1:25 



width protom.: width deutomerite.........! :2.2 1:2.8 1:2 1:3 1:3 



Diameter nucleus . 20 22 18 22 24 



CNEMIDOSPORA LUTEA Schneider 



[Figures 56 and 57] 

 1882 Cnemidospora lutea Schneider 1882:446-8 



Cnemidospora : Sporonts solitary, elongate. Total length 500/t. 

 Width not given. Ratio length protomerite : total length : : 1 : 15 ; 

 width protomerite : width deutomerite :: 1 : 1.6. Protomerite sub- 

 globular, broader than long, in the ratio of 4 : 3. Divided into two 

 parts, the anterior the shape of a double convex lens, without the charac- 

 teristic endocyte granules, and tinted greenish ; the posterior, larger, por- 

 tion containing yellow or brown endoplasmic granules. Deep constriction 



