Scanning electron microscopy of tests of Triticites ventricosus and Schwagerina sp. shows that the microgranular wall was secreted rather than agglutinated. Grains range in size from 0.5 to 6.0 μm, but grains larger than 4 μm are rare. Evidence that grains were secreted includes tight packing, uniform size and shape, and apparently homogeneous composition. Furthermore, scanning electron microscopy confirms the perforate nature of the antetheca and the nature of the keriothecal wall. Alveoli taper toward the tectum and pass through the tectum as tiny pores, enhancing communication between chambers and with the external environment.

The traditional model for the addition of chambers is rejected. Three ways in which new chambers may have been added to the test that are consistent with observations made here: 1) The antetheca may have thickened differentially, creating a substrate to which the keriotheca of the new chamber was attached; 2) Part of the tectum, septum, and keriotheca of the previous chamber may have been resorbed before calcite forming the new chamber was secreted, perhaps necessary because the tectum was an unsuitable substrate on which to attach the keriotheca of the new chamber; 3) A combination of the above may have occurred wherein the antetheca thickened differentially and was resorbed locally, providing a suitable substrate on which to attach the keriotheca of the new chamber. The last model is favored here because it best explains the shape of the septa and the configuration of the keriotheca of the chambers of most specimens. Nevertheless, the other two models are consistent with the morphology of some specimens.

Two new genera of Upper Silurian stromatoporoids in order Actinostromatida are described. Genus Bicolumnostratum Stock, with type species B. micum (Bogoyavlenskaya), is characterized by two kinds of pillars and nonaligned colliculi, and is assigned to family Actinostromatidae. Genus Acosmostroma Stock, with type species A. ataxium Stock new species, contains irregular micropillars and microcolliculi, and is assigned to family Densastromatidae. Two additional new species are Acosmostroma glascoense Stock and A.? cobleskillense Stock. A fourth species is A. tenuissimum (Parks). Bicolumnostratum is known from Ludlow- and Pridoli-age strata, whereas the occurrences of Acosmostroma are strictly Pridoli in age.

Faunules of largely hexactinellid sponges have been collected from siltstones of Early Silurian Wenlock or latest Landovery age within the upper Road River Group from northern British Columbia. The assemblages include the new species: Protospongia columbiana, Hexatractiella pseudonevadensis and Cyathophycus akiensis. Other taxa described include the hexactinellids Protospongia conica Rigby and Harris, 1979, Hexatractiella nevadensis (Rigby and Stuart, 1988), Diagoniella sp., Gabelia pedunculus? Rigby and Murphy, 1983, and a specimen of the monaxonid demosponge Wareiella typicala Rigby and Harris, 1979. Also included is a fragment of what must have been a steeply obconical-cylindrical hexactinellid sponge of uncertain taxonomy; it has a skeleton of robust hexactines in an unquadruled net, above a root-tuft of 10-20 spicules. Other sponge impressions include small circular clusters of hexactines with radiating, to basketlike patterns and somewhat similar, isolated and dissociated, long probably roof tuft spicules and possible basal root tuft rosettes of monaxons. The faunules are similar to other outer continental margin, black shale, sponge assemblages of the Early Paleozoic Era, and include elements previously described from northern British Columbia and central Nevada.

The sponge Neoguadalupia oregonensis new species is described from the Upper Triassic Martin Bridge Formation in the southern Wallowa Mountains, Oregon. It is the first authenticated Triassic occurrence of the genus Neoguadalupia, previously known from the Permian of South China and suspected to occur in Upper Triassic of Nevada. This discovery provides evidence at the generic level of survival of a Lazarus taxon in an island-arc terrane of western North America.

Anactolasma yukonanum new genus and species is described from the Pragian of Yukon Territory and is assigned to the Anactolasmatinae, a new subfamily of the Mucophyllidae Hill. Adult stages of Anactolasma resemble gerontic stages of Kobeha Merriam, although the genera have distinct ontogenies. Kobeha is revised on the basis of new material of its type species K. walcotti Merriam. The Papiliophyllinae Stumm are promoted to family status. Kobeha ketophylloides Merriam, from the Pragian of Nevada, and Endophyllum banksi Jell and Hill, from the Pragian of Tasmania, are restudied using new topotypic and other material. A new endophyllid genus named Murphyphyllum is erected for them, with E. banksi as type species. Asarcophyllum ramosum new genus and species, from the Emsian of Nevada, is made type species of a new cyathophyllid genus. Spongophyllum nevadense Stumm and S. expansum Stumm, both also from the Emsian of Nevada, are placed in the new genus, as is Asarcophyllum corona new genus and species, from the Emsian of Yukon Territory. Biostratigraphic settings, with emphasis on associated corals, brachiopods and conodonts, are given for the new and revised genera and species.

We describe three scleractinian corals and one species of hydrozoan from the New Pass Range, central Nevada, which together constitute the oldest Triassic cnidarian assemblage from North America. They occur in carbonate rocks tentatively correlated with the Augusta Mountain Formation, Star Peak Group. At generic and higher levels, these cnidarians seem representative of early Mesozoic Tethyan faunas and carbonate lithofacies, but they indicate some endemism. Although the original aragonitic skeletons and microstructure are destroyed by recrystallization, the corals still yield important details allowing their correct taxonomic assignment. They contain the minitrabecular cerioid coral, Ceriostella variabilis new genus and species, the thick-trabecular, thamnasteroid coral Mesomorpha newpassensis new species, and an undeterminable cuifastreid coral tentatively assigned to Cuifastraea. The discovery of Mesomorpha marks the first occurrence of this genus outside the Jurassic and Cretaceous seas. Also discovered is a remarkably corallike hydrozoan, Cassianastraea reussi (Laube), already known from the Carnian stage of the western Tethys. This is the first occurrence of this species outside the western Tethys.

An unusual, lichenoporid-like bryozoan colony from Mid-Silurian strata on Gotland is described as a new cystoporate, Inconobotopora lichenoporoides new genus and species; a poorly known form from the same area and approximate horizon is reclassified as Inconobotopora silurica (Hennig, 1906). Similarities in overall morphology, particularly flagged by the distinctive radial-disk construction, combine with geochronologic sequence to suggest the possibility of an evolutionary lineage from Ordovician Constellaria, through Silurian Inconobotopora, to Devonian Botryllopora, and perhaps even on to Cretaceous-Cenozoic-Recent Lichenopora (although this last extension is extremely difficult to demonstrate in the present state of knowledge).

Two new cirroidean gastropod genera, Alaskiella (family Porcelliidae) and Alaskacirrus (family Cirridae), from the Emsian (late Early Devonian) of west-central Alaska (Medfra B-4 quadrangle) are described. The shell of Alaskiella medfraensis new genus and species exhibits inclined heterostrophic coiling. This shell character is known among other members of the subclass Archaeogastropoda, but is recorded for the first time within members of the superfamily Cirroidea. Inclined heterostrophic coiling of the shell was probably developed independently in several different groups of the subclass Archaeogastropoda. The new genus Alaskacirrus, represented by Alaskacirrus bandeli new species, is the oldest and only known Paleozoic member of the family Cirridae. This suggests that the family Cirridae was separated from the family Porcelliidae since at least Early Devonian time and that it most probably developed from the subfamily Agnesiinae of the family Porcelliidae. Thus, the stratigraphic range of the family Cirridae is at least from Lower Devonian to Cretaceous, an interval of about 350 million years.

The following new Toernquistiidae from Whiterockian (Llanvirn to lower Caradoc) strata of the Precordillera, western Argentina, are described: Chomatopyge canasi new species, Lasarchopyge benedettoi new genus and species, Lasarchopyge correae new genus and species, Lasarchopyge new species A, and Paratoernquistia sanchezae new genus and species. Phylogenetic analysis suggests that the Toernquistiidae Hupé, 1953 (including Chomatopyge, Lasarchopyge, Mesotaphraspis, Paratoernquistia, and Toernquistia) is closely related to but distinct from the Dimeropygidae Hupé, 1953 (including Ischyrotoma, Ischyrophyma and Dimeropyge). It is difficult to find unique synapomorphies that unite toernquistiids and dimeropygids into a monophyletic group that excludes other proetides (e.g., hystricurids), although details of their ontogenies are similar. Several species of Toernquistiidae are known from the Argentine Precordillera (one species previously described), and other species of this family have been described from Australia, Baltica, China, Kazakhstan and Laurentia. Members of the Dimeropygidae are known only from Baltica and Laurentia.

The Ashgillian Pabos Formation underlies the Ashgillian-Llandoverian White Head Formation and consists, in the immediate Percé area, of 21 trilobite taxa. Of these, 11 are left in open nomenclature, four of which are summarily described, commented upon, and illustrated. Ten species are specifically determined and three of these are new: Remopleurides arenosus, Achatella (Achatella) clivosa, and Meadowtownella sacerdos. Hibbertia whittingtoni (McNamara, 1979) is a junior secondary homonym and renamed H. conistonensis. The Ashgillian-Llandoverian cheirurines of the Percé area are reviewed and new generic assignments suggested; these are a major component of the Pabos trilobite fauna. Revision of Ceraurinus icarus, a widely distributed North American species, shows its inherent variability; limits of variation, more complete descriptions, and stratigraphic distribution of most previously described species are also given. The distinctive trinucleid Novaspis elevata occurs in the Pabos, outside the immediate Perce area. Almost all of the Pabos trilobites are also present in the coeval Grande Coupe beds of the Matapedia Group; otherwise they are a mixture of taxa with greatest faunal affinities with North American or northwestern European taxa of the same age.

The scarce fossil record of stomatopod crustaceans is extended with three new species and two new genera described from the Miocene of California. Squilla laingae new species and Angelosquilla altamirensis new genus and species show clear affinities to the Recent family Squillidae. Topangasquilla gravesi new genus and species can be accommodated within the Recent family Lysiosquillidae. These new species occur in the Monterey and Topanga Formations in Los Angeles County. In addition, three other specimens are described from the Miocene Topanga Formation. The preservation of these stomatopods is among the best noted for any fossils of this group. These specimens show characteristic stages of decay that clearly correspond with those noticed in taphonomic experiments with Recent stomatopods.

Ninety-one specimens of Pentremites Say from the Mississippian Chesterian display color patterns. The darker color patterns represent a thin veneer of pigmented calcite which is barely visible on a polished surface or thin section, but which can be removed with dilute hydrochloric acid. Preservation appears to be best in specimens from shallow marine clays and shales. The patterns represent four color patterns, each consisting of different shades of calcite, and ranging in color from tan to black. Color patterns generally, but not always, cross growth lines. Type 1 has arched chevron patterns on the deltoids, horizontal lines on the radials, and triangular bands on the basals. Type 2 has darkened deltoids or concave chevrons on the deltoids and darkened areas concentric to the radials, and sometimes alternating light and dark bands conforming to growth lines on the radials. Type 3 has sloping lines crossing the radials, concave chevrons on the deltoids, and darkened areas on the lower radials, concentric to the ambulacra and on the basals. Type 4 has dark dots concentric to the lower ambulacra, arched chevrons on the deltoids and transverse lines abutting the radials and on the basals. The color patterns are original and may have been exposed on the outside of the integument.

The new asteroid species Sclerasterias zinsmeisteri (Asteriidae), Paragonaster clarkae, Tesselaster clarki (both Goniasteridae), and the new ophiuroid species Ophiura hendleri (Ophiuridae) are described from the late Eocene La Meseta Formation at Seymour Island, Antarctic Peninsula. The arm tip of an apparently new genus of the Oreasteridae is too incomplete to assign at the generic level. Other La Meseta asteroid species have been described elsewhere. Six of seven recognized stelleroid genera and all represented families survive, and differences between new species and existing congeneric species are subtle. Thus, the La Meseta fauna was similar to living faunas in basic composition.

Among La Meseta asteroids, Zoroaster aff. Z. fulgens and Ctenophoraster downeyae are known from numerous specimens; fossils of the other species are comparatively uncommon and given the uncertainties of sampling, further taxa might await discovery at Seymour Island. Although the Paxillosida is known from Jurassic rocks, fasciole-bearing, semi-infaunal genera are first known from Cretaceous deposits, and Astropecten and Astropecten-like Ctenophoraster are first recorded from Cenozoic rocks. Zoroaster and Tesselaster are only known from deep water settings today, although they are found in the La Meseta. Ophiura hendleri, the only ophiuroid recognized to date from the La Meseta, occurs singly, in small groups, and in Paleozoic-type ophiuroid-rich beds.

An early Devonian graptolite fauna is described from Lila and Huiku sections in Southwest Yunnan, China. Three graptolite biozones are recognized, which in ascending order are: Monograptus uniformis Biozone, M. hercynicus Biozone and M. falcarius Biozone. Six species are described in this paper: Monograptus uniformis Příbyl, M. aequabilis (Příbyl), M. microdon Richter, M. hercynicus Perner, M. falcarius Koren, and Abiesgraptus sp.

Four new species of cyathaspidid extend the range of the genus Poraspis back into the Late Silurian and indicate that the Canadian arctic was its center of origin. Poraspis heintzae n. sp., P. cracens n. sp., P. thules n. sp. and P. parmula n. sp. also increase the known geographic range of the genus which had previously been reported only from the District of Mackenzie (NWT, Canada), Spitsbergen, western and eastern Europe. The identification of P. sericea from the upper member of the Peel Sound Formation substantiates correlation of this interval with the crouchi zone of the Anglo-Welsh Borders, and provides another rare example of a species common to the Canadian arctic and European successions.

The taxonomy of the European stenonoid horses is revised using multivariate statistical techniques in this paper. The objectives are: to identify the taxonomic status of this group; to revise the specific and subspecific diagnoses, and the valid taxa; and to analyze their paleoecology and evolution. We conclude that: 1) there are six species among the Plio-Pleistocene European stenonoids: Equus major Depéret, in Delafond and Depéret 1893, ex Boule; Equus livenzovensis Bajgusheva, 1978; Equus stenonis Cocchi, 1867; Equus senezensis Prat, 1964; Equus altidens von Reichenau, 1915; and Equus sussenbornensis Wüts, 1901; 2) There are seven subspecies, three of E. stenonis, two of E. senezensis, and two of E. altidens; 3) There are two monophyletic groups according to the “neighbor-joining method,” one composed of the middle-to-small-size species, and the other of the biggest ones; 4) There is a trend toward decreasing body size through time in stenonoid horses. This trend, that follows the inverse direction of Cope's rule, can be related to the climatic-environmental changes that occurred from the middle Villafranchian to the early Galerian; 5) Large stenonoids were recorded in the middle Villafranchian and were associated with open and dry habitats (steppes), whereas the small ones lived in more closed and wet habitats (savanna-mosaic, woodlands) from late Villafranchian to earliest Galerian.

The results of the first comprehensive paleobotanical survey of the northern portion of the late Miocene Ogallala Group are discussed. Several species of fossilized fruiting structures from vascular plants (Berriochloa, Celtis, Cryptantha, Biorbia, Lithospermum, Eleofimbris, Carex, and Cyperocarpus) in the mid- to late-Miocene are reported. Fewer taxa (12 genera) were found in the South Dakota-northern Nebraska area than have been reported previously (20 genera) from southern Nebraska-Kansas strata in the same formations and approximately the same area of exposures. Sites of Barstovian age near the Kilgore Flora site indicate that grasses were commonly found in the region. The results presented here support the hypothesis that grassland savanna vegetation was widely distributed in the northern Great Plains by the Clarendonian age.

Organic-walled fossils, such as graptolites and Chitinozoa, show a high degree of transparency to near infrared radiation relative to visible light. Infrared video microscopy (IVM) provides real-time images of the three-dimensional form and internal structure of many specimens that are opaque to visible light. An infrared video camera can be mounted on a biological or petrographic, transmitted-light microscope, and with the addition of a monitor and video printer, images can be viewed and directly printed. With the use of a digital frame-capture system, the IVM images can be digitally stored for analysis, enhancement and printing. As compared with scanning electron microscopy, which only reveals the external form, IVM shows such features as fusellar growth bands and internal septa of graptolites and the prosome structure of Chitinozoa. This method eliminates the need for chemical clearing of specimens for study in visible light, which damages the surface texture and commonly renders specimens too brittle for further manipulation. Infrared video microscopy is potentially applicable to the study of any organic-walled fossils and to the petrographic study of sedimentary organic matter.

Wagler (1830) described a new genus of colubrid snake from Sri Lanka and assigned it the generic name Aspidura (Reptilia: Serpentes: Colubridae) for which the type species Aspidura brachyorrhos (Boie, 1827) (syn. Scytale brachyorrhos Boie, 1827) was placed. Since this description, five more species have been described and assigned to the genus: Aspidura copei Günther, 1864; Aspidura deraniyagalae Gans and Fetcho, 1982; Aspidura drummondhayi Boulenger, 1904; Aspidura guentheri Ferguson, 1876; and Aspidura trachyprocta Cope, 1860, all of which are geographically restricted to Sri Lanka.