292 
to the list. Forms whose antecedent minimum does not fall on 
June 28 or July 5 are designated by a superior 1; those whose 
maximum does not fall on July 19 or 26, by a superior 2; and those 
whose subsequent minimum is not on July 26 or August 2, by a 
superior 3. 
The component forms and groups are Crenothrix, etc.', total 
Schizophycee, Microcystis ichthyoblabe', total Chlorophycee, Actinas- 
trum hantzschu, Crucigenia rectangularis, Pediastrum boryanum' 8, 
P. pertusum®*, Raphidium polymorphum', Scenedesmus genuinus, 
S. obliquus, S. quadricauda, Schroederia setigera, total Bacillariacee’, 
Cyclotella kuetzingiana, Diatoma elongatum', Fragilaria virescens’, 
Melosira granulata var. spinosa’, M. varians’, Navicula spp., Synedra 
acus, total Conjugate’, Closterium acerosum, C. gracilis, total Protozoa, 
total Mastigophora, Eudorina elegans, Euglena acus, E. oxyurts, 
E. viridis, Glenodinium cinctum, Lepocinclis ovum, Pandorina 
morum®, Phacus longicauda':?,*, P. pleuronectes? *, Platydorina 
caudata, Pleodorina californica, Trachelomonas acuminata‘, T. 
hispida’, T. volvocina, total Rluzopoda, Difflugia globulosa, total 
Ciliata?, Codonella cratera®, Halteria grandinella® *, Tintinnidium 
fluviatile?: *, total Rotifera, total Bdelloida *, total Plorma, Anurea 
cochlearts and var. tecta, eggs of A. cochlearts and var. tecta, A. 
hypelasma, Asplanchna brightwellit:?.°, Brachionus angularis and 
var. bidens, eggs of B. angularis and var. bidens, B. bakert and vars. 
9 
clumiorbicularis!, melhem1, and tuberculus'*, total of all varieties 
of B. baker1, B. budapestinensis, B. militaris':*, B. pala and var. 
amphiceros, B. urceolaris var. bursartus, B. variabilis*: *, Mastigocerca 
carinata', Monostyla bulla, Polyarthra platyptera, eggs of P. platyp- 
tera®*, Rattulus tigris?, Syncheta pectinata', S. stylata, eggsof Syncheta', 
Triarthra terminalis? *, Pedalion mirum *, total Entomostraca’ 3, 
total Cladocera’ ?» *, Bosmina longirostris' *, Ceriodaphma scitula, 
Chydorus sphericus, Diaphanosoma brachyurum*, Moina micrura’* %, 
total Copepoda ' * *, Cyclops viridis var. brevispinosus and var. 
insectus, C. edax, young Cyclops', nauplii.of Copepoda’ *. 
An examination of the preceding list and of the qualitative data 
of Table I., reveals the fact that 71 of the more typical planktonts 
are found in appreciable numbers in the plankton during this 
month. To this number we may add 6 immature forms separately 
listed in the table and 14 group totals, making in all 91 sets of 
statistical data bearing on the components of this pulse. An analy- 
