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McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
An order of the class Hirudinea. These leeches possess an eversible proboscis and lack hemoglobin in the blood. They may be divided into two families, the Glossiphoniidae and the Ichthyobdellidea.
Industry:Science
An order of the class Hydrozoa of the phylum Coelenterata, characterized by an extremely complex organization of components of several different types, some having the basic structure of a jellyfish, others of a polyp. The components may be connected by a stemlike region or may be more closely united into a compact organism. The medusalike components include swimming bells, a gas-filled float, bracts which are tough gelatinous bodies presumed to be protective, and gonophores which produce the eggs and sperms. Polyplike components include gastrozooids with mouth and one long hollow tentacle; dactylozooids without mouth and often with one tentacle; and gonozooids which bear the gonophores.
Industry:Science
An order of the class Insecta known as the true flies and so named because they possess only two wings. This characteristic, together with a pair of balancers or halteres, distinguishes flies from all other orders of the Insecta. The three names for members of the order, known commonly as flies, gnats, or midges, form a part of the common names of most families, genera, and species of the order. The term fly also forms a part of the compound names of the insects in many other orders, such as butterfly, Mayfly, and chalcid fly, but when used alone it is correctly applied only to the members of the Diptera. The forms most commonly known as maggots are actually dipterous larvae, and keds (Hippoboscidae) are parasitic forms of flies that have lost their wings. The Diptera are the most important group of insects considered in medical entomology. Many, especially the mosquitoes, are the vectors for numerous parasites and diseases.
Industry:Science
An order of the class Insecta related to the order Hemiptera. This is a major group of sucking insects, with more than 30,000 species, even though in Asia and Africa the number of undiscovered species probably still exceeds the discovered ones. Common examples are the cicadas, aphids, and leafhoppers. The group is difficult to characterize because of the large number and diverse forms of the species it contains.
Industry:Science
An order of the class Insecta sometimes referred to as the Heteroptera. Both names refer to the forewings, which are differentiated into a thickened basal area and a membranous apical region. These are the true bugs. The related order, Homoptera, has forewings of uniform texture. Included in Hemiptera are such common insects as the bedbugs, stink bugs, plant bugs, lace bugs, and backswimmers.
Industry:Science
An order of the class Lycopsida (club mosses), regarded as more advanced than the extinct Protolepidodendrales because they produce spores of two sizes, but less advanced than the Lepidodendrales and Isoetales because they lack wood and finite growth. All are perennial herbs, varying in growth habit from prostrate to climbing.
Industry:Science
An order of the class Lycopsida (clubmosses) that is evolutionarily positioned between two extinct orders. The Lycopodiales are more advanced than the Asteroxylales because their sporangia are unequivocally positioned on the upper surface of modified leaves, but less advanced than the Protolepidodendrales because they lack a uniquely lycopsid feature termed the ligule. All have steles with metaxylem toward the center of the axis, but otherwise show considerable variation. All are perennial nonwoody herbs.
Industry:Science
An order of the class Phytamastigophorea, also known as the Dinoflagellata. Many botanists consider this group to be a member of the class Dinophyceae. <i>Noctiluca scintillans</i>, one of the largest species, may measure 0.06 in. (1.5 mm), whereas the flagellate state of some species may be as small as 10 micrometers. Although primarily marine, some dinoflagellates occur in fresh water. Some possess brown chromatophores, some are variously colored, and others are colorless. Masking pigments are frequent, occurring in the cytoplasm or in chromatophores. All types of nutrition exist, and some species are parasitic. Two flagella emerge laterally from a longitudinal depression or sulcus. An encircling flagellum in a groove or girdle divides the body into epicone and hypocone; the other, extending backward, propels the organism forward. The nucleus is very large.
Industry:Science
An order of the class Phytamastigophorea. Many botanists consider this group a part of the class Chrysophyceae, the golden-brown algae. Chrysomonads, also known as Chrysomonadina, are usually small flagellates, <i>Mallomonas</i> being about the largest. They are yellow to brown because of phycocrysin in the usual one or two chromatophores, but some lack chromatophores. <i>Uroglena</i> colonies may be quite large. Many species form diagnostic siliceous cysts. Palmelloid colonies (<i>Hydrurus</i>) consist of a tough, gelatinous matrix holding many nonflagellate cells. Starch is not formed, but fats are, and the refractive carbohydrate leucosin is common. The flagella are usually two, rarely three, and are subequal. Nuclei are small.
Industry:Science
An order of the class Reptilia (infraclass Archosauria) which is aquatic species including the alligators, caimans, crocodiles, and gavials. The group has a long fossil history from the Late Triassic, and its members are the closest living relatives of the extinct dinosaurs and the birds. The 23 living species are found in tropic areas of Africa, Asia, Austria, and the Americas. One form, the saltwater crocodile (<i>Crocodylus porosus</i>), has traversed oceanic barriers from the East Indies as far east as the Fiji Islands.
Industry:Science
