Genus: Cigar- or foot-shaped; a single macronucleus and 1 to several vesicular or compact microuclei (Kudo, 1966).
Species: Oblong; 50-105 (80-90) μm long; a compact micronucleus; two contractile vacuoles; fresh water (Kudo, 1966). Similar in shape to P. bursaria but much more rounded at both ends; 70-90 μm long; two conctractile vacuoles; a single ovoid macronucleus with a single micronucleus; caudal cilia present (Carey, 1992).
Generally believed P. trichium = P. putrinum (see below)
Google Image Search
P. trichium
98 x 48 μm
mac. spherical
Saitama, 1999
P. trichium
84-98 x 40 μm
Japan, 1998
P. trichium
93 x 55 μm
Oura central p.
Oura
Gunma, 2006
P. trichium
92 x 55 μm
drainage ditch
Kurihashi
Saitama, 2006
P. trichium
91 x 44 μm
mac. ellipsoidal
Japan, 1998
P. trichium
86-89 x 39-44 μm
Kanayama Green p.
Kiyose
Tokyo, 2003
P. trichium
86-89 x 39-44 μm
near Lake Aoki
Omachi
Nagano, 2006
P. trichium ?
83 x 45 μm
mac. ellipsoidal
Tochigi, 2001
P. trichium ?
83 x 40 μm
large Mic.
Bushi, Iruma
Saitama, 2002
P. trichium
78 x 39 μm
Konosu
Saitama, 2003
P. trichium
μm
near rice field
Yachiyo
Chiba, 2008
P. trichium
77 x 41 μm
Japan, 1999
P. trichium
70 x 34 μm
Shibu-ike
Shiga highland
Nagano, 2005