Translation 2816

36
broadly oval with slight indentation. Longitudinal
groove extends from the apex to the antapical end.
Very frequently the cells are non-motile.
Length 30-50A . . . . . . G. limneticum 27.
IT. Small to very small forms (small forms, 20-259 in lenüthtvery small
f orms , 7-12-15)4).
^a) Posterior part of body extends into three short, corniform
or conical processes. Anter.ior part of body is uniform, and
cupuliform. Measurements: 10-14 x 9-11A .. G. trS_ceratum 28.
(b) Posterior part of body does not extend into corniform processes.
1. The epivalve is often smaller than the hypovalve (often
nearly the same length).
o^)
The epivaïve â.s. hemisphericaï., Lhe hypova3.ve somewûat
thinner (truncatedly conical). Measurements: 8-17 x 6-12A.
(Tropical form?) . . . . . . . . . . . . G.yarians.,29.'
^3) The epivalve is cap--shaped, broadly rounded, as wide as
the hypovalve, but lower. The hypovalve is semicircular.
Measurements 13-14 x 11R. .. .. G. profundum 30-
2. Epivalve and hypovalve approximately the same size. (116)
oC) Cells are ovoid. The epivalve-is half-oval to hemispherical.
The hypovalve is half-oval, projecting a little more
widely. Measurements 20-24 x 16kk. (Tropical form?)
bogoTiense 32.
/3) The epivalve is elongate half-oval, the hypovalve hemispherical.
Measurements 17-18 x 10K .- G. lacustre 32.