M. Koidzumi 261 
distinguished them as Teratonymjpha mirabilis (type species) and its variety 
formosana, respectively. 
(1) Teratonymjpha mirabilis gen. nov. et sp. nov. (Plate XII, figs. 26-31, 
and Text-figs. A and B). 
This is one of the largest of the protozoa in Japanese termites and much 
the largest of the forms found in Leucotermes ; and its large size, coupled with 
its monstrous appearance, at once attracts the observer’s attention. Ordinarily 
the organism assumes the shape of a club, being rounded at the anterior end 
and somewhat pointed posteriorly. The differentiation of the parts of the 
body of this organism is far more remarkable than in Trichonymjpha and 
Pseudotrichonymjpha. The anterior portion of the body has a remarkably 
complicated construction, and the posterior region appears very peculiar, 
being apparently segmented like a cestode. The specially differentiated 
anterior part, or head, has the shape of a concavo-convex lens. The body is 
widest near the head and gradually decreases in diameter towards the posterior 
end. The organism usually measures 200-250 /x, but sometimes 300 /x or more, 
in length, and 40-50 p, in width at the widest portion. In the posterior region 
the body wall is not smooth, but is provided with numerous transverse and 
more or less prominent and sharp ridges, which are inclined backwards. The 
regular metameric arrangement of these ridges gives the body the segmented 
appearance which suggests the proglottids of a tape-worm. The appearance 
of the endoplasm also tempts one to think that the body is made up of 
successive segments, as in the cestodes. But careful observations reveal that 
the differentiation is limited to the body wall, and no septa are to be found 
crossing the endoplasm. The number of the ridges varies from 18 to 30, 
or sometimes even more, in proportion to the length of the body. As the 
animalcules are subjected to unfavourable conditions, their shape changes 
more or less quickly to that of a spindle or turnip, until finally they become 
rounded and burst. The flagella are very conspicuous in this form. Very 
long ones are found closely distributed at the head, as in the preceding genera. 
On the surface of the body, however, they are not distributed diffusely, but 
are arranged in parallel rows, each of the transverse ridges being provided 
with one row of them. 
The head consists of two parts; namely, a thick axial column or cylinder 
and a peripheral layer traversed by numerous flagella, arising at the surface 
of the column. The peripheral layer encircles the axial column from top to 
base, leaving the frontal surface uncovered, and becomes gradually thinner 
towards the sides as it curves backwards. The axial column itself is ordinarily 
barrel-shaped, being slightly narrowed towards the top and the base. It 
measures some 10 p, in breadth and 15/x in height. Its shape is, however, 
variable to a certain extent, and it is often narrowed at the anterior end only. 
Its complicated organization is shown in Text-fig. A. As it is quite trans¬ 
parent, the details of its structure can be made out in the living organism. 
