THE PROTOZOA PARASITIC IN ARCHOTERMOPSIS WROUGHTONI 249 
General Considerations. 
Systematic Position. 
That P. pristina is a flagellate belonging to the order 
Hypermastigina (Grassi) is indubitable. The Tricho- 
nymphidae have suffered much at the hands of sys- 
tematists. Stem (26) in 1878 correctly placed them among 
the flagellates, though Leidy (21, 22) himself considered them 
as intermediate between the gregarines and ciliates. Kent (14) 
in 1882 founded the famly Trichonymphidae and 
placed it among the holotrichous ciliates, a view supported 
by Butschli in 1889. Senn (25) in 1900 added these forms, 
as an appendix to the Flagellata ; while Hickson (10) allocated 
them to an appendix of the Cihata. 
In the 1911 edition of Doflein’s text-book the classification 
of Senn was followed ; but in the last edition of 1916 Grassi’s 
correct classification is given. 
Finally, in 1913 Poche (28) added his quota to the existing 
confusion by creating the new order Trichonympha, 
which was placed among the Kuflagellata. Kofoid and 
Swezy (17, 18) have recently published papers dealing with 
the flagellate affinities of these organisms, to which those 
interested are referred. One point which appears to have 
escaped notice is the complete absence of a micronucleus in 
any of the Hypermastigina, a fact which in itself is 
suggestive of their flagellate affinities, for with a few doubtful 
exceptions the ciliates are all heterokaryote, as Hickson pointed 
out in 19038. 
P. pristina so differs from Hartmann’s male form of 
T. hertwigi that the two forms cannot be regarded as 
one species. Grassi distinguishes four species of Pseudo - 
trichonympha, none of which appear to be identical 
with P. pristina. The descriptions given of the species, 
however, are so scanty that it is impossible adequately to 
compare them with the animal described here. 
