592 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
the Flagellata, and the Tintinna among the Ciliata. Both groups, and 
particularly the Noctilucide, belong to the neritic plankton. They occur 
in the oceanic only where the coast water flows in (6, pp. 679, 750, 933). 
The common Noctiluca miliaris and some related species sometimes 
cover the surface of the coast waters in such masses as to form a thick 
reddish-yellow slime, often like ‘“‘tomato soup,” and at night are 
brightly luminous. ‘The Tintinnoide (Tintinnus, Dictyocysta, Codonella) 
appear in smaller quantities, but often in great numbers. Some forms 
of these elegant Ciliata are oceanic. 
Thalamophora (Foraminifera).—The Thalamophora, often and very 
properly called Foraminifera, were once generally regarded as ben- 
thonic. New observations first showed that a part of these are plank- 
tonic, and through the comprehensive series of observations by the 
Challenger the abundant occurrence of these pelagic Foraminifera and 
their great part in the formation of that most important sediment, the 
Globigerina ooze, was first established. All these Thalamophora of the 
plankton belong to the peculiar perforated Polythalamia, to the family 
ot the Globigerinide; only Orbulina (provided it is independent) to the 
Monothalamia. The number of their genera (8-10) and species (20-25) 
is relatively small, but the number of individuals is inconceivably 
great. By far the most important and numerous belong to the genera 
Globigerina, Orbulina, and Pulvinulina; after these Spheroidina and 
Pullenia. They occur everywhere in the open ocean in numberless 
myriads. J. Murray could often from a boat scoop up thick masses of 
them with a glass, and never fished with the tow net in 200 fathoms 
without obtaining some (5, p. 534). A few forms (Hastigerina and 
Cymbalopora) show more local increase in numbers, while others are 
rare everywhere (Chilostomella, Candeina). In the equatorial counter- 
currents of the Western Pacific, between the equator and the Caroline 
Islands, the Challenger found “great banks of pelagic foraminifera. 
On one day an unheard-of quantity of Pulvinulina was taken in the 
tow nets; on the foliowing day they were entirely absent, and Pul- 
lenia was extraordinarily abundant.” These important observations 
by Murray I can confirm from my own experience in the Atlantic and 
Indian oceans* (comp. 3, pp. 166, 188). 
*The important relations of these pelagic Polythalamia to the rest of the fauna of 
the plankton on the one side, as well as its importance in the formation of the “Globi- 
gerina ooze” on the other, has been expressly stated by Murray (6, p. 919). I agree 
completely with him in the view that these oceanic Globigerinide are true pelagic 
rhizopods, which in part are found swimming only at the surface or at slight depths 
(autopelagic), in part at zones of different depths (zonary), but they are not ben- 
thonic. The enormous sediment of ‘‘Globigerina ooze” is composed of the sunken’ 
calcareous shells of the dead pelagic animals. On the other hand, the benthonic 
thalamophores, living partly abyssal, on the bottom of the deep sea, partly littoral, 
creeping among the forests of seaweed on the coasts, are of other species and genera. 
They develop a much greater variety of form. The neritic thalamophores found 
swimming in the coast waters are in part again characterized by various forms. 
