A bog pond 4 km east of Yellowstone Lake has a pollen record starting with an Artemisia spruce assemblage, implying alpine vegetation. A layer of volcanic ash, dated as 14,360 ± 400 BP (probably Glacier Peak or Mt. St. Helens J), occurs within the zone, which terminates at 11,630 ± 180 BP. The rest of the pollen sequence is dominated by lodgepole pine, with reappearance of spruce pollen in modest quantities about 4500 BP, according to dating provided by a layer of Mt. Mazama ash (6600 BP). The present vegetation of the area is marked by forests of lodgepole pine with some stands of spruce and fir. The pollen sequence suggests that the upper treeline before 11,600 y. a. was perhaps 500 m lower than today. The climate then became warmer and/or drier than today (Altithermal interval). About 4500 y. a., a slight climatic reversal took place, roughly contemporaneous with the regrowth of glaciers in the western mountains (neoglaciation).

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Azo dyes bearing acrylamide groups were synthesized and copolymerized with acrylic and methacrylic acids to yield photochromic polyelectrolytes. The optical behavior of the isomerizing side chains was qualitatively studied, especially the cis + trans isomerization process, and compared with that of corresponding alkylamide dyes (copolymerized monomer dye models), which are also photochromic and moderately soluble in water. Preliminary comparison of adsorption bound dyes was made. The geometry of the various dyes can be switched a t will by irradiation, but the relaxation processes vary with environment of the dye, so that three distinct types of dye are defined: free dyes, adsorption bound dyes, and covalently bound (or tethered) dyes. All these behave reversibly and react with nucleophilic catalysts. In the case of the tethered dyes, irradiation response and dark relaxation behavior are linked to the charge and conformation of the copolyelectrolyte.

Sixteen species of the brachiopod subfamily Spiriferellinae Waterhouse are described from the Upper Carboniferous and Early to Middle Permian beds of the Yukon Territory and the Canadian Arctic Archipelago. New taxa are Spiriferella primaeva n. sp., S. yukonensis n. sp., S. leviplica n. sp., Eridmatus petita n. sp., Elivina cordiformis n. sp., Plicatospiriferella canadensis n. gen., n. sp., and Alispiriferella ordinaria (Einor) n. gen. The remaining species are all shared with the Soviet Union and/or Arctic islands such as Greenland and Spitzbergen, apart from the poorly known species S. arctica (Haughton). Spirifere lla tibetana of Chernyshev not Diener in the Urals is renamed Elivina tschemyschewi, and Spiriferella saranae Chernyshev not de Verneuil is renamed S. barkhatovae n. sp. It is shown that pustules formed on the shell surface at roughly weekly intervals and that mature shells lived for up to four years. Some species tolerated a wide range of lithofacies, whereas others were restricted to a muddy or silty seafloor. A few spiriferellin species commonly were sympatric: Alispiriferella ordinaria (Einor) with S. saranae (de Verneuil), and Timaniella harkeri Waterhouse with Spiriferella loveni (Diener) or S. keilhavii (von Buch). The common species were relatively long lived through three to four brachiopod zones and moderately widespread over the globe. They also tolerated some range in temperature, but they avoided glaciated regions near the South Pole in east Australia, the highly saline Zechstein Sea, and paleotropical realms such as Armenia and China, though appearing at some paleotropical horizons in Laos, Fergana and Texas. A summary of world distribution and interrelationships shows several major lineages in Spiriferella. The predominant one included the widespread Spiriferella saranae (de Verneuil), which may have evolved later into two other widespread species, S. keilhavii (von Buch) and S. rajah (Salter). Another, less dominant, lineage with short incurved umbo included Spiriferella pseudodraschei Einor and other forms restricted to the Northern Hemisphere. Yet another suite of species with round-crested fold (S. wimani) ranged into both hemispheres. Eridmatus Branson was chiefly a Middle and Late Carboniferous genus of limited distribution, closely allied to Spiriferella. Elivina Frederiks was of modest significance but ranged widely, whereas the short-lived Middle Permian genus Timaniella Barkhatova was restricted to the Northern Hemisphere. Alispiriferella also was limited to the Northern Hemisphere, as was Plicatospiriferella.

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