Anchylosis or Ankylosis

(Gr. ankulos, crooked). The union of two bones by osseous matter, so that they become one bone, or are immovably joined together.

Androgynous

(Gr. aner, a man ,• gune, a woman). Synonymous with hermaphrodite, and implying that the two sexes are united in the same individual.

Androphores

(Gr. aner, a man ; and phero, I carry). Applied to medusiform gonophores of the Hydrozoa, which carry the spermatozoa, and differ in form from those in which the ova are developed.

Annelida

(a Gallicised form of Annulata). The Ringed Worms, which form one of the divisions of the Anarthropoda.

Annulated

Composed of a succession of rings.

Annuloida

(Lat. annulus, a ring; Gr. eidos, form). The sub-kingdom comprising the Echinodermata and the Scolecida ( =Echinozoa).

Annulosa

(Lat. annulus). The sub-kingdom comprising the Anarlhropoda and the Arthropoda or Articulata, in all of which the body is more or less evidently composed of a succession of rings.

Anomodontia

(Gr. anomos, irregular; odous, tooth). An extinct order of Reptiles, often called Dicynodontia.

Anomura

(Gr. anomos, irregular ; oura, tail). A tribe of Decapod Crustacea, of which the Hermit-crab is the type.

Anoplura

(Gr. anoplos, unarmed: oura, tail). An order of Apterous Insects.

Anoura

(Gr, a, without; oura, tail). The order of Amphibia comprising the Frogs and Toads, in which the adult is destitute of a tail. Often called Batrachia.

Antennae

(Lat. antenna, a yard-arm). The jointed horns or feelers possessed by the majority of the Articulata.

Antennules

(dim. of antennas). Applied to the smaller pair of antennae in the Crustacea.

Antibrachium

((Jr. anti, in front of; brachion, the arm). The fore-arm of the higher Vertebrates, composed of the radius and ulna.

Antlers

Properly the branches of the horns of the Deer tribe (Cervidae), but generally applied to the entire horns.

Antlia

(Lat. antlia, a pump). The spiral trunk or proboscis with which Butterflies and other Lepidopterous Insects suck up the juices of flowers.

Aphaniptera

(Gr. aphanos, inconspicuous; pteron, a wing). An order of Insects comprising the Fleas.

Aplacentalia

The section of the Mammalia, comprising the two divisions of the Didelphia and Monodelphia, in which the young is not furnished with a placenta.

Apoda

(Gr. a, without; podes, feet). Applied to those fishes which have no ventral fins. Also to the footless Caeciliae amongst the Amphibia.

Apodal

Devoid of feet.

Apodemata

(Gr. apodaio, I portion off). Applied to certain chitinous septa which divide the tissues in Crustacea.

Aptera

(Gr. a, without; pteron, a wing). A division of Insects, which is characterised by the absence of wings in the adult condition.