=

124 MusEuM AND Art NoTES

Tintinnidae, from the Strait of Georgia, B.C.

By G. H. WaltLes

we

N pursuance of the plan of illustrating in Museum and Art Notes various groups of
the local fauna, in this number two plates of the Tintinnidae are given.
These plates appeared originally in Contributions to Canadian Biology, N. S.,
Vol. 2, Part 2, 1925; this being now out of print, the Biological Board of Canada have
kindly loaned the plates for reproduction.

The extended descriptions of each species are now, however, omitted; all the
species illustrated were found in the Strait of Georgia and most of them in the
vicinity of the Biological Station at Departure Bay, Nanaimo, during the years 1923
and 1924.

The only additions to the list since that date are four species recorded from the
west coast of Vancouver Island in plankton, collected by Dr. H. C. Williamson;
illustrations of three of these appeared in Museum Notes, Vol. 3, plate 12, December,
1928, namely:

Cyttarocylis denticulata var gigantea (Branot); Figure 41.
Cyttarocylis edentata (Brandt); Figure 42.

Dictyocysta elegans (Ehrenb) ; Figure 29.

Dictyocysta templum (Haeckel).

The last named is similar to D. elegans, except that the fenestration of the collar
is single, that is, the outer row of openings extend down to the shoulder of the test.

Three species of Laboea, a genus closely allied to the Tintinnidae, were also found
in the plankton from the west coast of Vancouver Island; namely, Laboea conica
Lohmann, L. acuminata Lugaard, L. comucopiae Wailes.

The Tintinnidae are Protozoa belonging to the Class Ciliata, sub-order Oligot-
richa; they frequently form an appreciable portion of marine and fresh-water plank-
ton; the animals are more or less funnel-shaped when extended, the anterior part
projecting from the test (shell) ; they swim rapidly with darting movements by means
of a wreath of membranelles (plumose cilia) which are arranged around the anterior
end; between these may be short tentaculae; inside this wreath is a funnel-shaped
opening leading to the gullet and stomach; on one side, the ventral, is a slit or cleft
bordered by a ciliated membrane.

Multiplication takes places by fission accompanied by mitotic division of the two
nuclei and two micronuclei, which is the number present in most, if not all. of the
species; the posterior animal retains the test and may assist the other in making a
new one, in which process the ciliated membrane is brought into use. An individual
in which division is in an advanced stage is shown on plate 2, figure 7.