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Alegret, Ortiz & Kaminski (eds.), 2012. Ninth International Workshop on Agglutinated Foraminifera, Abstract Volume Quinterno, P.J. 1968. Distribution of recent foraminifera in central and south San Francisco Bay. M.S. thesis, San Jose State College, San Jose, California. Slater, R.A. 1965. Sedimentary environments in Suisun Bay, California. M.A. thesis, University of Southern California, Los Angeles, California. Wagner, D.B. 1978. Environmental history of central San Francisco Bay with emphasis on foraminiferal paleontology and clay mineralogy. Ph.D. Dissertation, University of California, Berkeley, California. 63
Alegret, Ortiz & Kaminski (eds.), 2012. Ninth International Workshop on Agglutinated Foraminifera, Abstract Volume Reinvestigation of two agglutinated genera of the order Textulariida Delage et Herouard, 1896 (Foraminifera) Valeria MIKHALEVICH Zoological Institute Russian Academy of Sciences, 199134, St. Petersburg, Russia. e-mail: mikha97@mail.ru Two species of the two genera (Norvanganina Mikhalevich, 1981 and Spirotextularia Saidova, 1975) of the order Textulariida Delage et Herouard, 1896, gathered first near the western coast of Africa near Monrovia and Canaries (depth 57 – 620 m) and the second near subtropical part of Atlantic South American coast (depth 38 – 200 m) were previously investigated in our material in the light microscope only (Mikhalevich, 1978, 1981). They were restudied here in SEM. Loeblich & Tappan (1987) considered Norvanganina to be “probably synonymous” to Textularia and marked that its canaliculate wall was not demonstrated. They also supposed the openings situated along the peripheral margin to be “result of breakage”. The study of the type species of Norvanganina – N. pseudorugos fistulosa Mikhalevich, 1981(= Textularia valeriae Loeblich & Tappan, 1987) in SEM had distinctly showed the canaliculate character of its wall. But this canaliculate wall has also a peculiar feature: very dense canaliculate perforations piercing its rather thick wall are covered from above with a thin layer with only rare irregulary disposed subcircular openings of somewhat larger size than densely dispersed regular canaliculate openings. These pseudopore openings are often encircled by a slight rim of the finer material. Thus between this superficial cover and the canaliculated wall the irregular partial additional space is present. A similar shell wall was described in some Sahulia (genus of Loeblich & Tappan, 1985) species by Hottinger et al. (1993). Openings rather regularly disposed along the peripheral margins of N. pseudorugosa fistulosa at the lateral edges of their chambers and leading to the chamber lumens are also encircled with a slight rim of finer material which would not be the case if they were a mere breakings. Between these peripheral openings and chamber lumen no chamberlet separated by a sieve plate exists, but the tube wider in diameter than canaliculi and alined from the inside with the organic matter just as in the more narrower canaliculi joins the chamber lumen with the surrounding space. All these structural features give reason to consider them as additional apertures. In Spirotextularia floridana (Cushman, 1922) chamberlets situated between the additional aperture and chamber lumen separated from the latter by the sieve plate are clearly observed similarly as seen in some other Spirotextularia species investigated earlier by Loeblich & Tappan (1985) (in the type species of the genus) and by Hottinger et al. (1993). Spirotextularia having dictinctly expressed planospiral coil in its initial part belongs to Spirotextulariinae Saidova, 1975, Norvanganina – to Textulariinae Ehrenberg, 1838. Additional peripheral apertures were also observed in some other agglutinated genera: Sahulia Loeblich & Tappan, 1985 (Textulariinae), Plotnikovina Mikhalevich, 1981 and Siphoniferoides Sidova, 1981 (Siphoniferoidinae Loeblich & Tappan, 1985 of the family Pseudogaudryinidae Loeblich & Tappan, 1985, order Verneuilinida Mikhalevich & Kaminski, 2004). Thus additional apertures in different agglutinated multichambered genera having different arrangement of their initial shell part and erected elongated biserial or triserial later part demonstrate formation of additional peripheral apertures in parallel in different groups. 64
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