278 Intestinal Protozoa in Termites 
variable in form, and, when alive, is frequently club-shaped or pear- 
shaped. 
The periplast is fairly well-developed and distinct ridges are found on the 
body wall, winding spirally from the anterior tip to the posterior end. The 
direction of the spiral is also right-handed in this form 1 . The edge of each 
ridge seems rather sharp and stiff, especially in the anterior region, so that 
it appears as though supported by a cord. The number of ridges seems to 
be eight. They are sloped backwards and at the posterior edge of each of 
them a shallow but distinct groove is formed behind; also a distinct row of 
basal granules of the flagella is there found, embedded in clear protoplasm. 
These spiral ridges are thus identical with the spiral ridges in Holomastigotoides, 
and represent the same type of structure as is seen in the well-developed 
transverse ridges in the body wall of Teratonympha. The disposition of the 
flagella is also identical with that of Teratonympha and Holomastigotoides . 
The basal end of each flagellum is adherent to the surface of the ridge and 
becomes free at its edge, so that the surface of the body between the ridges or 
folds appears beautifully and densely striped (PI. XIII, figs. 39, 53 c). The 
free portion of the flagellum measures 10-15 /i. The endoplasm is rather 
clear, and usually contains a large number of small refringent globules (“round 
corpuscles” of Grassi), taking haematoxylin and eosin somewhat deeply 
(PL XIII, fig. 40). It is peculiar to this form that wood particles and other 
food debris are not usually present in the endoplasm. 
The nucleus is situated at a short distance from the anterior tip, and is 
usually pear-shaped. There is a mass of peculiar dense protoplasm, as seen 
in the preceding genera, at the anterior tip of the body, and the nucleus is 
usually found embedded in it. The internal structure of the nucleus is some¬ 
what peculiar in this form. It consists of a structureless ground substance, 
staining rather deeply with iron-haematoxylin, and having several chromatin 
masses embedded in it. 
I have found no other stages of development than that just described, 
and I have encountered no dividing forms in my preparations. 
(2) Pyrsonympha Series. 
This group embodies a number of forms clearly distinguished from the 
members of the previous series. In them the body is not invested with 
numerous flagella resembling cilia, but is provided with peculiar slender 
flagellum-like cords, four or eight in number, which I propose to call “ flagellar 
cords” (“undulating lines” of Leidy, and “contractile cords” of Porter). It 
is true that, in some forms, delicate appendages are found distributed over 
the body, giving it the appearance of being invested with cilia; but these 
appendages are quite different in nature from ordinary cilia or flagella, and 
are something like those seen at the posterior end of Holomastigotoides and 
1 Drawn right-handed by both Grassi (1917) and Porter (1897, Plate III, figs. 30-32, 35, 36). 
