188 MARIE V. LEBOUR. 
Genus AMPHIDINIUM Cl. and L. 
(59) N.R. Amphidinium crassum Lohmann. I have referred to this 
species, a form between A. crassum and A. longum of Lohmann, 
but which is slightly larger than either of these (Fig. 2). 
The shape of the body is not so pointed posteriorly as in A. longum 
but not so broadly rounded as in 4. crassum, the greatest breadth 
being in about the centre of the body. The nucleus is posterior 
as in both forms, and a coloured body, greenish, is situated just 
in front of the nucleus and behind the transverse groove, with 
small refractive bodies scattered round it. This is perhaps the 
remains of ingested food material. A thin transparent covering 
can sometimes be seen detaching itself from the body. Length 
Fig. 2.—Amphidinium crassum Lohmann. x 466. N=nucleus. 
of body 0-030 mm. The only record so far of this species is by 
Lohmann from Kiel. 
Genus GYMNODINIUM Stein. 
(40) LR. Gymnodinium teredo Pouchet. Fairly common in July and 
August in the water samples in 1915, less common in 1916. This 
is the only gymnodinian found here in the winter months, but 
then only rarely. It turns up singly nearly all the year round. 
Many abnormalities and deformities occur and a variety of shapes 
is seen. 
(41) N.R. G. pseudonoctiluca Pouchet (Fig. 3). To this species 
I refer one which agrees well with one condition of the above 
species, but which I never saw with the long contractile tentacle 
described by Pouchet (1885). It only occurred twice, the first 
time in medium tow nettings in July, 1915, and the second time 
in the water samples in June, 1916. It is rather smaller than the 
type (length 0-10 mm.). The ventral surface on each side of the 
longitudinal groove is pulled out into a flap, the left flap shghtly 
longer than the right. The bright yellow chromatophores radiate 
from the centre. The longitudinal groove is more marked than 
in Pouchet’s figures. The nucleus is in the centre of the body. 
