stalk, as Kent '81 suspected. The anterior process with its pigment
spot; the cirri, the spherical nucleus, the position of the vacuole,
etc., are all opposed to such an interpretation which Kent applied to
the original species. Neither can it be a Tintinnoid. I place it
provisionally as _S. caudatum_.


KEY TO THE MARINE GENERA OF TINTINNIDÆ.

Diagnostic characters: Body attached by a stalk to a cup. Inside the
zone of membranelles is a ring of cilia (par-oral).

1. The test is gelatinous and more or Genus _Tintinnidium_
less covered by foreign particles

2. The test is chitinous and clear. Genus _Tintinnus_
No foreign particles.

3. The test is chitinous; covered by Genus *_Tintinnopsis_
foreign particles, growth rings
frequent

4. The test is chitinous, often Genus _Codonella_
covered by foreign particles.
The test is marked by discoid,
circular, or hexagonal spots.

5. The test is perforated by pores Genus _Dictyocysta_
of circular or hexagonal form.