44 SHALLOW-WATER FORAMINIFERA OF TORTUGAS REGION. 
has been assumed by most writers that the color of the test in certain 
of the Rotaliide, for example in Discorbis, was due to the con- 
tained protoplasm. I had supposed that the specimens with deep 
color were specimens in the living condition when taken. Heron- 
Allen makes a similar note (loc. cit., footnote, page 257) in speaking 
of Tretomphalus bulloides as follows: 
“The color varies from pure white to a deep brown, owing to the contained 
protoplasm, which is frequently as dark as in Discorbina mediterranensis 
(d’Orbigny) and therefore of that group.” 
In crushing specimens which had a series of dark-brown chambers 
in the rotaliform portion, I found a thin, nearly transparent brown 
lining that could be separated from the interior of these chambers, 
after which they were white. This lining seemed structureless, 
suggesting a chitinous character, and appeared to be the source of 
the color in the chambers. The specimens had not been dried and 
the lining was of uniform character and thickness, and could scarcely 
have been dried protoplasm. It may be suggested that a similar 
condition should be looked for in other colored Rotaliidx, especially 
where the early chambers only are colored. 
When the “‘float-chamber’”’ was removed the under side of the 
rotaliform portion had the appearance shown in figure 3, very 
different from even the small specimens of Cymbalopora poeyi. The 
suggestion that Tretomphalus bulloides is a stage of Cymbalopora, or 
of Planorbulina, or of Discorbis does not seem to hold in the Tortugas 
region. All the pelagic specimens of Tretomphalus bulloides were 
much smaller than those of Cymbalopora poeyi and had a different 
shape and general character. The ventral side does resemble that 
of Cymbalopora poeyi, but only in a general way. It may be that 
these small forms are all megalospheric and are thus producing the 
sexual zoospores for the formation of the microspheric generation, 
but no specimens referable to the latter were found in the tow-nets 
during my stay at the Tortugas. 
A peculiar character of the pores of the test was noted, as shown. 
The early chambers have comparatively large pores, which in- 
crease in numbers but decrease in size in the succeeding chambers 
until in the ‘‘balloon-chamber”’ they are very fine, except for the 
large pores at the base. 
A preliminary study of abundant material of Tretomphalus bul- 
loides from Samoa, collected by Dr. Alfred G. Mayor, seems to show 
that a very different species of the genus is developed there and that 
instead of T'retomphalus and its enlarged “‘balloon-chamber” being 
a stage in several genera, as suggested by Heron-Allen, it seems 
really to be a genus with several distinct species with definite dis- 
tributions. This is further indicated by the second species, 
Tretomphalus millettii (Heron-Allen, and Earland), which is known 
from the Indo-Pacific. 
