The Ancient Life History of the Earth / A Comprehensive Outline of the Principles and Leading Facts of Palæontological Science

by Henry Alleyne Nicholson

HALITHERIUM (Gr. hals, sea; therion, beast). An extinct genus of Sea-cows (Sirenia).
HAMITES (Lat. hamus, a hook). A genus of the Ammonitidœ.
HELIOPHYLLUM (Gr. helios, the sun; phullon, leaf). A genus of Rugose Corals.
HELLADOTHERIUM (Gr. Hellas, Greece; therion, beast). An extinct genus of Ungulate Mammals.
HEMIPTERA (Gr. hemi, and pteron, wing). An order of Insects in which the anterior wings are sometimes "hemelytra."
HESPERORNIS (Gr. Hesperos, the evening star; ornis, bird). An extinct genus of Birds.
HETEROCERCAL (Gr. heteros, diverse; kerkos, tail). Applied to the tail of Fishes when it is unsymmetrical, or composed of two unequal lobes.
HETEROPODA (Gr. heteros, diverse; podes, feet). An aberrant group of the Gasteropods, in which the foot is modified so as to form a swimming organ.
HIPPARION (Gr. hipparion, a little horse). An extinct genus of Equidœ.
HIPPOPOTAMUS (Gr. hippos, horse; potamos, river). A genus of Hoofed Quadrupeds—the "River-horses."
HIPPURITIDÆ. (Gr. hippos, horse; oura, tail). An extinct family of Bivalve Molluscs.
HOLOPTYCHIUS (Gr. holos, whole; ptucé, wrinkle). An extinct genus of Ganoid Fishes.
HOLOSTOMATA (Gr. holos, whole; stoma, mouth). A division of Gasteropodous Molluscs, in which the aperture of the shell is rounded, or "entire."
HOLOTHUROIDEA (Gr. holothourion, and eidos, form). An order of Echinodermata comprising the Trepangs.
HOMOCERCAL (Gr. homos, same; kerkol, tail). Applied to the tail of Fishes when it is symmetrical, or composed of two equal lobes.
HYBODUNTS (Gr. hubos, curved; odous, tooth). A group of Fishes of which Hybodus is the type-genus.
HYDROIDA (Gr. hudra; and eidos, form). The sub-class of the Hydrozoa, which comprises the animals most nearly allied to the Hydra.
HYDROZOA (Gr. hudra; and zoön, animal). The class of the Cœlenterata which comprises animals constructed after the type of the Hydra.
HYMENOPTERA (Gr. humen, a membrane; pteron, a wing). An order of Insects (comprising Bees, Ants, &c.) characterised by the possession of four membranous wings.

ICHTHYODORULITE (Gr. ichthus, fish; dorus, spear; lithos, stone). The fossil fin-spine of Fishes.
ICHTHYOPTERYGIA (Gr. ichthus; pterux, wing). An extinct order of Reptiles.
ICHTHYORNIS (Gr. ichthus, fish; ornis, bird). An extinct genus of Birds.
ICHTHYOSAURIA (Gr. ichthus; saura, lizard). Synonymous with Ichthyopterygia.
IGUANODON (Iguana, a living lizard; Gr. odous, tooth). A genus of Deinosaurian Reptiles.
INCISOR (Lat. incido, I cut). The cutting teeth fixed in the intermaxillary bones of the Mammalia, and the corresponding teeth in the lower jaw.
INEQUILATERAL. Having the two sides unequal, as in the case of the shells of the ordinary bivalves (Lamellibranchiata). When applied to the shells of the Foraminifera, it implies that the convolutions of the shell do not lie in the same plane, but are obliquely wound round an axis.
INEQUIVALVE. Composed of two unequal pieces or valves.
INOCERAMUS (Gr. is, a fibre; keramos, an earthen vessel). An extinct genus of Bivalve Molluscs.
INSECTA (Lat. inseco, I cut into). The class of articulate animals commonly known as Insects.
INSECTIVORA (Lat. insectum, an insect; voro, I devour). An order of Mammals.
INSECTIVOROUS. Living upon Insects.
INSESSORES (Lat. insedeo, I sit upon). The order of the Perching Birds, often called Passeres.
INTERAMBULACRA. The rows of plates in an Echinoid which are not perforated for the emission of the "tube-feet."
INTERMMAXILLÆ or PRÆMAXILLÆ. The two bones which are situated between the two superior maxillæ in Vertebrata. In man, and some monkeys, the præmaxillæ anchylose with the maxillæ, so as to be irrecognisable in the adult.
INVERTEBRATA (Lat. in, without; vertebra, a bone of the back). Animals without a spinal column or backbone.
ISOPODA. (Gr. isos, equal; podes, feet). An order of Crustacea in which the feet are like one another and equal.

KAINOZOIC (Gr. kainos, recent; zoe, life). The Tertiary period in Geology comprising those formations in which the organic remains approximate more or less closely to the existing fauna and flora.

LABYRINTHODONTIA (Gr. laburinthos, a labyrinth; odous, tooth). An extinct order of Amphibia, so called from the complex microscopic structure of the teeth.
LACERTILIA (Lat. lacerta, a lizard). An order of Reptilia comprising the Lizards and Slow-worms.
LAMELLIBRANCHIATA (Lat. lamella, a plate; Gr. bragchia, gill). The class of Mollusca comprising the ordinary bivalves, characterised by the possession of lamellar gills.
LEPIDODENDRON (Gr. lepis, a scale; dendron, a tree). A genus of extinct plants, so named from the scale-like scars upon the stem left by the falling off of the leaves.
LEPIDOPTERA (Gr. lepis, a scale; pteron, a wing). An order of Insects, comprising Butterflies and Moths, characterised by possessing four wings which are usually covered with minute scales.
LEPIDOSIREN (Gr. lepis, a scale; seiren, a siren—the generic name of the Mud-eel or Siren lacertina). A genus of Dipnoous fishes, comprising the "Mud-fishes."
LEPIDOSTROBUS (Gr. lepis, a scale; strobilos, a fir-cone). A genus founded on the cones of Lepidodendron.
LEPTÆNA (Gr. leptos. slender). A genus of Brachiopods.
LINGULA (Lat. lingula, a little tongue). A genus of Brachiopods.
LYCOPODIACEÆ (Gr. lupos, a wolf; pous, foot). The group of Cryptogamic plants generally known as "Club-mosses."

MACHÆRACANTHUS (Gr. machaira, a sabre; acantha, thorn or spine). An extinct genus of Fishes.
MACHAIRODUS (Gr. machaira, a sabre; odous, tooth). An extinct genus of Carnivora.
MACROTHERIUM (Gr. makros, long; therion. beast). An extinct genus of Edentata.
MACRURA (Gr. makros, long; oura, tail). A tribe of Decapod Crustaceans with long tails (e.g., the Lobster, Shrimp, &c.)
MAMMALIA (Lat. mamma, the breast). The class of Vertebrate animals which suckle their young.
MANDIBLE (Lat. mandibulum, a jaw). The upper pair of jaws in Insects; also applied to one of the pairs of jaws in Crustacea and Spiders, to the beak of Cephalopods, the lower jaw of Vertebrates, &c.
MANTLE. The external integument of most of the Mollusca, which is largely developed, and forms a cloak in which the viscera are protected. Technically called the "pallium."
MANUS (Lat. the hand). The hand of the higher Vertebrates.
MARSIPOBRANCHII (Gr. marsipos, a pouch; bragchia, gill). The order of Fishes comprising the Hag-fishes and Lampreys, with pouch-like gills.
MARSUPIALIA (Lat. marsupium, a pouch). An order of Mammals in which the females mostly have an abdominal pouch in which the young are carried.
MASTODON (Gr. mastos, nipple; odous, tooth). An extinct genus of Elephantine Mammals.
MEGALONYX (Gr. megas, great; onux, nail). An extinct genus of Edentate Mammals.
MEGALOSAURUS (Gr. megas, great; saura, lizard). A genus of Deinosaurian Reptiles.
MEGATHERIUM (Gr. megas, great; therion, beast). An extinct genus of Edentata.
MESOZOIC (Gr. mesos, middle; and zoe, life). The Secondary period in Geology.
MICROLESTES (Gr. mikros, little; lestes, thief). An extinct genus of Triassic Mammals.
MILLEPORA (Lat. mille, one thousand; porus, a pore). A genus of "Tabulate Corals."
MIOCENE (Gr. meion, less; kainol, new). The Middle Tertiary period.
MOLARS (Lat. mola, a mill). The "grinders" in man, or the teeth in diphyodont Mammals which are not preceded by milk-teeth.
MOLLUSCA (Lat. mollis, soft). The sub-kingdom which includes the Shell-fish proper, the Polyzoa, the Tunicata, and the Lamp-shells; so called from the generally soft nature of their bodies.
MOLLUSCOIDA (Mollusca; Gr. eidos, form). The lower division of the Mollusca, comprising the Polyzoa, Tunicata, and Brachiopoda.
MONOGRAPTUS (Gr. monos, single; grapho, I write). A genus of Graptolites.
MYLODON (Gr. mulos, a mill; odous, tooth). An extinct genus of Edentate Mammals.
MYRIAPODA or MYRIOPODA (Gr. murios, ten thousand; podes, feet). A class of Arthropoda comprising the Centipedes and their allies, characterised by their numerous feet.

NATATORES (Lat. nare, to swim). The order of the Swimming Birds.
NATATORY (Lat. nare, to swim). Formed for swimming.
NAUTILOID. Resembling the shell of the Nautilus in shape.
NERVURES (Lat. nervus, a sinew). The ribs which support the membranous wings of insects.
NEUROPTERA (Gr. neuron, a nerve; pteron, a wing). An order of Insects characterised by four membranous wings with numerous reticulated nervures (e.g., Dragon-flies).
NEUROPTERIS (Gr. neuron, a nerve; pteris, a fern). An extinct genus of Ferns.
NOTHOSAURUS (Gr. nothos, spurious; saura, lizard). A genus of Plesiosaurian Reptiles.
NOTOCHORD (Gr. notos, back; chorde, string). A cellular rod which is developed in the embryo of Vertebrates immediately beneath the spinal cord, and which is usually replaced in the adult by the vertebral column. Often it is spoken of as the "chorda dorsalis."
NUDIBRANCHIATA (Lat. nudus, naked; and Gr. bragchia, gill). An order of the Gasteropoda in which the gills are naked.
NUMMULINA (Lat. nummus, a coin). A genus of Foraminifera, comprising the coin-shaped "Nummulites."

OBOLELLA (Lat. dim. of obolus, a small coin). An extinct genus of Brachiopods.
OCCIPITAL. Connected with the occiput, or the back part of the head.
OCEANIC. Applied to animals which inhabit the open ocean (= pelagic).
ODONTOPTERYX (Gr. oduos, tooth; pterux, wing). An extinct genus of Birds.
ODONTORNITHES (Gr. oduos, tooth; ornis, bird). The extinct order of Birds, comprising forms with distinct teeth in sockets.
OLIGOCENE (Gr. oligos, few; kainos, new). A name used by many Continental geologists as synonymous with the Lower Miocene.
OPHIDIA (Gr. ophis, a serpent). The order of Reptiles comprising the Snakes.
OPHIUROIDEA (Gr. ophis, snake; oura, tail; eidos, form). An order of Echinodermata, comprising the Brittle-stars and Sand-stars.
ORNITHOSCELIDA (Gr. ornis, bird; skelos, leg). Applied by Huxley to the Deinosaurian Reptiles, together with the genus Compsognathus, on account of the bird-like character of their hind-limbs.
ORTHIS (Gr. orthos, straight). A genus of Brachiopods, named in allusion to the straight hinge-line.
ORTHOCERATIDÆ (Gr. orthos, straight; keras, horn). A family of the Nautilidœ, in which the shell is straight, or nearly so.
ORTHOPTERA (Gr. orthos, straight; pteron, wing). An order of Insects.
OSTEOLEPIS (Gr. osteon, bone; lepis, scale). An extinct genus of Ganoid Fishes.
OSTRACODA (Gr. ostrakon, a shell). An order of small Crustaceans which are enclosed in bivalve shells.
OTODUS (Gr. ota, ears; odous, tooth). An extinct genus of Sharks.
OUDENODON (Gr. ouden, none; odous, tooth). A genus of Dicynodont Reptiles.
OVIBUS (Lat. ovis, sheep; bos, ox). The genus comprising the Musk-ox.

PACHYDERMATA (Gr. pachus, thick; derma, skin). An old Mammalian order constituted by Cuvier for the reception of the Rhinoceros, Hippopotamus, Elephant, &c.
PALÆASTER (Gr. palaios, ancient; aster, star). An extinct genus of Star-fishes.
PALÆOCARIS (Gr. palaios, ancient; karis, shrimp). An extinct genus of Decapod Crustaceans.
PALÆOLITHIC (Gr. palaios, ancient; lithos, stone). Applied to the rude stone implements of the earliest known races of men, to the men who made these implements, or to the period at which they were made.
PALÆONTOLOGY (Gr. palaios, ancient; and logos, discourse). The science of fossil remains or of extinct organised beings.
PALÆOPHIS (Gr. palaios, ancient; ophis, serpent). An extinct genus of Snakes.
PALÆOSAURUS (Gr. palaios, ancient; saura, lizard). A genus of Thecodont Reptiles.
PALÆOTHERIDÆ. (Gr. palaios, ancient; ther, beast). A group of Tertiary Ungulates.
PALÆOZOIC (Gr. palaios, ancient; and zoe, life). Applied to the oldest of the great geological epochs.
PARADOXIDES (Lat. paradoxus, marvellous). A genus of Trilobites.
PATAGIUM (Lat. the border of a dress). Applied to the expansion of the integument by which Bats, Flying Squirrels, and other animals support themselves in the air.
PECOPTERIS (Gr. peko, I comb; pteris, a fern). An extinct genus of Ferns.
PECTEN (Lat. a comb). The genus of Bivalve Molluscs comprising the Scallops.
PECTORAL (Lat. pectus, chest). Connected with, or placed upon, the chest.
PENTACRINUS (Gr. penta, five; krinon, lily). A genus of Crinoids in which the column is five-sided.
PENTAMERUS (Gr. penta, five; meros, part). An extinct genus of Brachiopods.
PENTREMITES (Gr. penta, five; trema, aperture). A genus of Blastoidea, so named in allusion to the apertures at the summit of the calyx.
PERENNIBRANCHIATA (Lat. perennis, perpetual; Gr. bragchia, gill). Applied to those Amphibia in which the gills are permanently retained throughout life.
PERISSODACTYLA (Gr. perissos, uneven; daktulos, finger). Applied to those Hoofed Quadrupeds (Ungulata) in which the feet have an uneven number of toes.
PETALOID. Shaped like the petal of a flower.
PHACOPS (Gr. phaké, a lentil; ops, the eye). A genus of Trilobites.
PHALANGES (Gr. phalanx, a row). The small bones composing the digits of the higher Vertebrata. Normally each digit has three phalanges.
PHANEROGAMS (Gr. phaneros, visible; gamos, marriage). Plants which have the organs of reproduction conspicuous, and which bear true flowers.
PHARYNGOBRANCHII (Gr. pharugx, pharynx; bragchia, gill). The order of Fishes comprising only the Lancelet.
PHASCOLOTHERIUM (Gr. phaskolos, a pouch; therion, a beast). A genus of Oolitic Mammals.
PHRAGMACONE (Gr. phragma, a partition; and konos, a cone). The chambered portion of the internal shell of a Belemnite.
PHYLLOPODA (Gr. phullon, leaf; and pous, foot). An order of Crustacea.
PINNATE (Lat. pinna, a feather). Feather-shaped; or possessing lateral processes.
PINNIGRADA (Lat. pinna, a feather; gradior, I walk). The group of Carnivora, comprising the Seals and Walruses, adapted for an aquatic life. Often called Pinnipedia.
PINNULÆ. (Lat. dim. of pinna). The lateral processes of the arms of Crinoids.
PISCES (Lat. piscis, a fish). The class of Vertebrates comprising the Fishes.
PLACOID (Gr. plax, a plate; eidos, form). Applied to the irregular bony plates, grains, or spines which are found in the skin of various fishes (Elasmobranchii).
PLAGIOSTOMI (Gr. plagios, transverse; stoma, mouth). The Sharks and Rays, in which the mouth is transverse, and is placed on the under surface of the head.
PLATYCERAS (Gr. platus, broad; keras, horn). A genus of Univalve Molluscs.
PLATYCRINUS (Gr. platus, broad; krinom, lily). A genus of Crinoidea.
PLATYRHINA (Gr. platus, broad; rhines, nostrils). A group of the Quadrumana.
PLATYSOMUS (Gr. platus, wide; soma, body). A genus of Ganoid Fishes.
PLEISTOCENE (Gr. pleistos, most; kainos, new). Often used as synonymous with "Post-Pliocene."
PLEUROTOMARIA (Gr. pleura, the side; tomé, notch). A genus of Univalve shells.
PLIOCENE (Gr. pleion, more; kainos, new). The later Tertiary period.
PLIOPITHECUS (Gr. pleion, more; pithekos, ape). An extinct genus of monkeys.
PLIOSAURUS (Gr. pleion, more; saura, lizard). A genus of Plesiosaurian Reptiles.
POLYCYSTINA (Gr. polus, many; and kustis, a cyst). An order of Protozoa with foraminated siliceous shells.
POLYPARY. The hard chitinous covering secreted by many of the Hydrozoa.
POLYPE (Gr. polus, many; pous, foot). Restricted to the single individual of a simple Actinozoön, such as a Sea-anemone, or to the separate zooids of a compound Actinozoön. Often applied indiscriminately to any of the Cœlenterata, or even to the Polyzoa.
POLYPORA (Gr. polus, many; poros, a passage). A genus of Lace-corals (Fenestellidœ).
POLYTHALAMOUS (Gr. polus; and thalamos, chamber). Having many chambers; applied to the shells of Foraminifera and Cephalopoda.
POLYZOA (Gr. polus; and zoön, animal). A division of the Molluscoida comprising compound animals, such as the Sea-mat—sometimes called Bryozoa.
PORIFERA (Lat. porus, pore; and fero, I carry). Sometimes used to designate the Foraminifera, or the Sponges.
PRÆMOLARS (Lat. prœ, before; molares, the grinders). The molar teeth of Mammals which succeed the molars of the milk-set of teeth. In man, the bicuspid teeth.
PROBOSCIDEA (Lat. proboscis, the snout). The order of Mammals comprising the Elephants.
PROCŒLOUS (Gr. pro, before; koilos, hollow). Applied to vertebræ the bodies of which are hollow or concave in front.
PRODUCTA (Lat. productus, drawn out or extended). An extinct genus of Brachiopods, in which the shell is "eared," or has its lateral angles drawn out.
PROTICHNITES (Gr. protos, first; ichnos, footprint). Applied to certain impressions in the Potsdam sandstone of North America, believed to have been produced by large Crustaceans.
PROTOPHYTA (Gr. protos; and phuton, plant). The lowest division of plants.
PROTOPLASM (Gr. protos; and plasso I mould). The elementary basis of organised tissues. Sometimes used synonymously for the "sarcode" of the Protozoa.
PROTOROSAURUS or PROTEROSAURUS (Gr. protos, first; orao, I see or discover; saura, lizard: or proteros, earlier; saura, lizard). A genus of Permian lizards.
PROTOZOA (Gr. protos; and zoön, animal). The lowest division of the animal kingdom.
PSAMMODUS (Gr. psammos, sand; odous, tooth). An extinct genus of Cestraciont Sharks.
PSEUDOPODIA (Gr. pseudos, falsity; and pous, foot). The extensions of the body-substance which are put forth by the Rhizopoda at will, and which serve for locomotion and prehension.
PSILOPHYTON (Gr. psilos, bare; phuton, plant). An extinct genus of Lycopodiaceous plants.
PTERANODON (Gr. pteron, wing; a, without; odous, tooth). A genus of Pterosaurian Reptiles.
PTERASPIS (Gr. pteron, wing; aspis, shield). A genus of Ganoid Fishes.
PTERICHTHYS (Gr. pteron, wing; ichthus, fish). A genus of Ganoid Fishes.
PTERODACTYLUS (Gr. pteron, wing; daktulos, finger). A genus of Pterosaurian Reptiles.
PTEROPODA (Gr. pteron, wing; and pous, foot). A class of the Mollusca which swim by means of fins attached near the head.
PTEROSAURIA (Gr. pteron, wing; saura, lizard). An extinct order of Reptiles.
PTILODICTYA (Gr. ptilon, a feather; diktuon, a net). An extinct genus of Polyzoa.
PTYCHOCERAS (Gr. ptucé, a fold; keras, a horn). A genus of Ammonitidœ.
PULMONATE. Possessing lungs.
PYRIFORM (Lat. pyrus, a pear; and forma, form). Pear-shaped.

QUADRUMANA (Lat. quatuor, four; manus, hand). The order of Mammals comprising the Apes, Monkeys, Baboons, Lemurs, &c.

RADIATA (Lat. radius, a ray). Formerly applied to a large number of animals which are now placed in separate sub-kingdoms (e.g., the Cœlenterata, the Echinodermata, the Infusoria, &c.)
RADIOLARIA (Lat. radius, a ray). A division of Protozoa.
RAMUS (Lat. a branch). Applied to each half or branch of the lower jaw, or mandible, of Vertebrates.
RAPTORES (Lat. rapto, I plunder). The order of the Birds of Prey.
RASORES (Lat. rado, I scratch). The order of the Scratching Birds (Fowls. Pigeons, &c.)
RECEPTACULITES (Lat. receptaculum, a storehouse). An extinct genus of Protozoa.
REPTILIA (Lat. repto, I crawl). The class of the Vertebrata comprising the Tortoises, Snakes, Lizards, Crocodiles, &c.
RETEPORA (Lat. reté, a net; porus, a pore). A genus of Lace-corals (Polyzoa).
RHAMPHORHYNCHUS (Gr. rhamphos, beak; rhugchos, nose). A genus of Pterosaurian Reptiles.
RHINOCEROS (Gr. rhis, the nose; keras, horn). A genus of Hoofed Quadrupeds.
RHIZOPODA (Gr. rhiza, a root; and pous, foot). The division of Protozoa comprising all those which are capable of emitting pseudopodia.
RHYNCHOLITES (Gr. rhugchos, beak; and lithos, stone). Beak-shaped fossils consisting of the mandibles of Cephalopoda.
RHYNCHONELLA (Gr. rhugchos, nose or beak). A genus of Brachiopods.
RODENTIA (Lat. rodo, I gnaw). An order of the Mammals; often called Glires (Lat. glis, a dormouse).
ROTALIA (Lat. rota, a wheel). A genus of Foraminifera.
RUGOSA (Lat. rugosus, wrinkled). An order of Corals.
RUMINANTIA (Lat. ruminor, I chew the cud). The group of Hoofed Quadrupeds (Ungulata) which "ruminate" or chew the cud.