Genus: Oral cavity deep, opens ventrally away from apex; more internal tubular part precedes cytostome; the tubular part of oral vacity extends to left (Illustrated Guide, 1985). Body laterally compressed (Carey, 1992).
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P. nasuta
125 x 60 μm
Japan, 199?
P. nasuta
131 x 70 μm
Uruguay, 1999