b. Proboscis not marked off from Genus *_Loxophyllum_
main body; body flat;
both surfaces striated

2. a. Mouth runs the entire length Genus _Amphileptus_
of proboscis; entire body
uniformly ciliated

b. Mouth runs the entire length Genus *_Lionotus_
of proboscis; body flat; right
side only is ciliated

c. Proboscis much drawn out, Genus _Dileptus_
flexible; mouth at its base

* Presence at Woods Hole indicated by asterisk.


Genus LOXOPHYLLUM Dujardin '41.

(Duj. '41; Wrzesniowski '69; Quennerstedt '65; '67; Cohn '66; Entz
'84; Gourret & Roeser '88; Bütschli '88; Shevyakov '96.)

The body is flat and somewhat leaf-shape, flexible, and elastic. The
anterior end is somewhat proboscis-like and flexible, but is not
sharply demarcated as in _Lionotus_. The central portion of the body
is developed into a more or less arched dorsal mass, which usually
contains the nuclei and contractile vacuoles. As a result of this
local thickening, the body is surrounded by a thin hyaline margin.
This, however, may be absent on the right side in some species. The