Fie REIS 7 pee 
clear longitudinal depression. Anterior end 
broad and rounded; posterior end pointed, 
but not tail like; one of the two margins 
of the body thicker and more convex than 
the other; cytostome oblique or almost paral- 
lel with the longitudinal axis, ending at 
the limit between the narrower margin and 
the anterior end. _ : 
In another form, Ch. caviae is short, from 
8 to 10 u long'andfrom 4 to 5 wide. Extre- 
-mities equally rounded and very broad; it 
shows a longitudinal depression; one of the 
margins is thick, rounded and very convex ; 
the other is much narrower, almost blade-like 
and only very slightly convex. The cytostome 
is perpendicular to the longitudinal axis and 
ends at the most anterior part of the narrow 
margin. There is a clear curve at the limit 
of the narrow margin and the thick part of 
the body; it is concave towards the margin 
and sometimes seems continuous with the 
edge of the cytostome; the flagella are often 
hidden near the concave side, in a bundle; 
cytostome generally like a sac and often 
narrower at its opening; it is about 1,5 or 
2 u wide at its broadest and 3 or 4 u long. 
Plasm divided inendo and ectoplasm. 
The latter forms a thick capsule-like peri- 
plastic layer, preventing any movements ; the 
rest of the ectoplasm is hyaline and conti- 
nuous with the endoplasm, which contains 
many irregular, siderophilous granulations, 
especially in the center. 
Nucleus difficult to see because of the 
large number of siderophilous granulations ; 
with large caryosome and empty clear zone. 
Blepharoplast, also difficult io distinguish, 
near the cytostome and connected with the 
nucleus by a rhizoplast. From it and pas- 
sing through the cytostome start four anterior 
flagella, which are more or less as long as 
the body; in the broad forms they sometimes 
form a bundle, the free end of which his 
hidden in the concavity limiting the narrow 
body margin. 
Habitat: Coecum of Cavla aperea and 
Cavia porcellus. 

Chilomitus lagostomi FONSECA, 1916. 
Redescription: Body elongate, more or 
less pear-shaped, flat, rigid, not metamor- 
phic. Length 11-15 mw, width —7 u: Ante- 
rior end rounded, blunt; posterior end slight- 
ly sharpened, but not in the shape of a real 
tail. At the fore end a short cytostome run- 
ning backwards obliquely; it is like a short 
sac and, though easily seen in fresh speci- 
mens, it is difficult to discern after staining, 
when it sometimes appears as a hyalin space 
in the granular cell; as it has no chromo- 
philous lip, it has no distinct outline in the 
stained body; from it four equal flagella 
run forwards; they emerge from the only, 
blepharoplast, which is not always easiy seen 
and lies at theanteriorend ofthe body; the 
flagella are slender, and of equal length, ge- 
nerally inferior to that of the cell. Proto- 
plasm hyaline, rarely alveolar, mostly devoid 
of any structure; it is divided ina thin layer 
of so sligthly chromophilus periplast that at 
times it is almost imperceptible and so rigid, 
as to prevent any movement, and an endo- 
plasm full of chromophilous granulations, 
which are either rounded or sometimes elon- 
gated; some of them are seen at the inner 
border of the periplastic layer forming a 
discontinous or regular lining. These granu- 
lations are a tittle less chromophilous than 
the nuclear masses, but not always easy to 
distinguish from them. 
The nucleus is an anterior, rounded or so- 
metimes alittle elongate mass which at times 
seems clearly formed of contiguous large mas- 
ses of chromatin; it is surrounded by a clear 
zone, which may be considered fluid, the 
chromatic mass being a caryosome. 
The smaller size, the more rounded form 
of the siderophilous granulations in the en- 
doplasm, the apparently greater richness in 
nuclear chromatin, making the nucleus more 
visible, which characterise this species, distin- 
guish it from the only other known one, 
which is the type species: Chilomitus caviae 
FONSECA 1915. The latter alsohas a mark- 
ed dimorphism and deep Jateral depressions 

