. Bulletins of American paleontology. 158 Bulletin 235. Text-figure 5. Early growth stages of Globigerino'ides sacculijer (Brady). Stages are progressively older from A to D. VS 45, Gulf of California, 17 cm net tow, 0-50 m. X ca. 160. USNM No. 643110. two types. Such minor differences are familiar to workers concentrating on a short stratigraphic sequence in a particular area, and while useful are of value only to that specific worker. It seems senseless to clutter up the classification with such, because so much confusion can be caused by misinterpretation. The lectotype chosen by Banner and
. Bulletins of American paleontology. 158 Bulletin 235. Text-figure 5. Early growth stages of Globigerino'ides sacculijer (Brady). Stages are progressively older from A to D. VS 45, Gulf of California, 17 cm net tow, 0-50 m. X ca. 160. USNM No. 643110. two types. Such minor differences are familiar to workers concentrating on a short stratigraphic sequence in a particular area, and while useful are of value only to that specific worker. It seems senseless to clutter up the classification with such, because so much confusion can be caused by misinterpretation. The lectotype chosen by Banner and Blow does not show this type of sac-chamber. G. sacadifer is an interesting species because of the unusual character- istics of the early chambers, which are difi^erent from those of such species as G. riiher or G. conglohatus. Text-fig. 5 shows a sequence of young specimens at various stages of growth. The early chambers can be seen so much more easily in plankton specimens than in fossil ones that these figured specimens were taken from a Gulf of California plankton sainple. The first two whorls form a test that is flat on the coiled side, has six-seven chambers in the first whorl, and a finely perforate glassy wall. Later, the chambers begin to increase inuch more rapidly in size and the characteristic coarse pores and long spines begin to appear. The early flattened part can be seen even in adult specimens, although often considerable wall thicken- ing has taken place. This early stage differs greatly from those of G. ruber and G. conglohatus^ which have an initial whorl of fiv^e rounded, globiger- ine Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Paleontological Research Institution (Ithaca, N. Y. ); Columbia University. Ithaca, N. Y. , Paleontological Research Institution [etc. ]
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