154 ILLINOIS BIOLOGICAL MONOGRAPHS [364 



tion 1/4 as long as the protomerite is high. Endocyte dense. Nucleus 

 spherical. 



Cysts spherical to slightly ovoidal, 120 by 108^. Spores unknown. 



Taken in the Province of Izu, Japan. Host: Tribolium ferrugi- 

 neum F. Habitat: Intestine. 



The character of the epimerite is evidence that this species is rightly 

 placed. 



STEININA ROTUNDA Watson 



[Figure 173] 



1915 Steinina rotunda Watson 1915 :32-3 



Host : Amara angustata Say. Taken at St. Joseph, 111., November, 

 1914. Habitat : Intestine. 



A dozen individuals were found in a single host. The sporonts are 

 solitary, the body stout, short and broad. The epimerite persists even 

 on some of the largest individuals. It is a spherical, sessile or shortly 

 stalked and hyaline knob. The protomerite just below it is broadly coni- 

 cal in shape, widening rapidly downward to form a cylinder bulging in 

 the middle portion. A deep constriction is present at the septum. The 

 protomerite is widest three fourths of its length from the anterior end, 

 and, without the epimerite, it is as high as wide. The deutomerite is 

 practically spherical except in its anterior end, which, at the septum, is 

 more or less flattened or sometimes concave downward. The deutomerite 

 widens rapidly from the septum and is as wide as long. 



In color, the body is light brown or tan, of equal density in both pro- 

 tomerite and deutomerite ; the protoplasm is homogeneous and not very 

 abundant. The anterior half of the protomerite and the epimerite is 

 transparent. The nucleus is visible in vivo in specimens of all ages. In 

 all the specimens attached to the epithelium, no matter how large, the 

 nucleus contains but one karyosome ; in the free individuals, no matter 

 how small, a large number of small deeply staining chromosomes are 

 present. The epicyte is thin and of equal width throughout. Longitudi- 

 nal striations are visible. 



Most of the specimens seen possessed epimerites, whether free or at- 

 tached. A goodly number of these, however, were free in the lumen. 

 The epimerite disappears by being gradually constricted off. When the 

 specimens are on a slide in a water medium for fifteen minutes, approxi- 

 mately, the epimerite breaks, the supposition being that it is highly por- 

 ous and the sudden strain caused by media of unequal density outside 

 and inside is reduced by the bursting of this fragile structure. When 



