198 MARIE V. LEBOUR. 
parent case in which it rotates freely on its longitudinal axis. It 
is fusiform in shape, and pointed in much the same way at both 
ends. The transverse furrow makes three complete turns and is 
deeply grooved. The longitudinal furrow is inconspicuous, making 
over one turn round the body. Nucleus nearly central. Length 
of body 0-05 mm., length of case 0-65 mm. This species is very 
similar to Pouchetia fusus Schiitt, but without the conspicuous 
lens and stigma of that form. 
Genus PoucHETIA Schiitt. 
(56) N.R. Pouchetia armata Dogiel (1906). This species, with its charac- 
teristic stinging capsules, is common in the water samples, especially 
in May and June. It is sometimes contained in a case, sometimes, 
and more usually, free. Division into two within the case was seen. 
So far this species has only been recorded for the Mediterranean. 
(57) N.R. Pouchetia parva Lohmann. This is fairly frequent in summer, 
especially in June. The case fits very close to the body, much 
closer than in P. armata. Division in the case is often seen. This 
species is very like Pouchet’s figure (1885) of P. polyphemus v. 
migra, the pigment, however, in his species is red and this is always 
black. 
(58) N.R. Pouchetia fusus Schiitt (1895). Occurs rarely in September. _ 
Conspicuous from its elongated body and large lens with dark 
red pigment. In one case the pigment mass was breaking up 
into small red spots. The specimens seen were always free. 
Genus PoLyKrikos Biitschli. 
(59) N.R.  Polykrikos Schwarzii Biitschli. Occurs occasionally in tow 
nettings and water samples from May throughout the summer. 
PYROCYSTEZ Apstein. 
Genus Pyrocystis Murray. 
(60) Pyrocystis lunula Schiitt. Occurs occasionally in tow nettings in 
August and September in various stages of division in the semilunar 
cases. 
Incertae sedis. 
(61) N.R. Oxyrrhis marina (Duj.). The position of Oxyrrhisis stilla vexed 
question, and although Senn (1910) regards it as a true peridinian, 
the view is not universally accepted (see Klebs, 1912). In my 
opinion it is more of a peridinian than a true flagellate, the division 
