THE MICROPLANKTON OF PLYMOUTH SOUND. 159 
(1) Mesodirium sp. Common in water samples. 
(5) Nassula sp. Rare from May to August, water samples. 
(5) Strombidtum caudatum From. Rare in summer, water samples. 
Genus LABoEA Lohmann. 
The species of this genus, so far as I have seen, all have a 
yellow colour. They are common in- the summer but occur all 
through the year although very rare in winter. Some of 
the most delicate of the Infusoria. Never found in the tow 
nettings. 
(7) Laboea conica Lohm. The commonest species of the genus. 
Occurs fairly often through the summer, but never in large 
numbers. 
(8) L. strobila Lohm. Occasionally from July to November and also in 
January 
(9) L. acuminata Leegaard. Occasionally through the year, chiefly 
in May. 
(10) L. spiralis Leegaard. Rare, May and July. 
(11) L. sp. All through the year several unidentified species occurred, 
except for part of December and January. 
(12) Lohmanmiella oviformis Leegaard. Rare, only in August, water 
samples. 
(13) Huplotes vannus O.F.M. Once only in July, water samples. 
(14) #. sp. Rare, September, water samples. 
(15) Tintinnus subulatus Ehr. From July to October, not uncommon, 
most frequent in August. 
(16) Tintinnopsis berordea (Stein). Very common, both in tow nettings 
and water samples, but especially in the former early in November, 
middle of December, end of March and again through July and 
August : at other times not so frequent. Almost absent through 
October and the latter part of September. 
(17) 7. campanula (Khr.). Occasionally at intervals from August to 
March, not observed from April to July. Both in tow nettings 
and water samples. 
(18) 7. ventricosa Cl. and L. Common at intervals throughout the year. 
Commonest in September. In both tow nettings and water 
samples, but commonest in the water samples. 
