Maxillipeds Sentence Examples
Muller, our leading authority, adopts the confusing plan of calling them second maxillae in the Cypridinidae (including Asteropidae), maxillipeds in the Halocypridae and Cyprididae, and first legs in the Bairdiidae, Cytheridae, Polycopidae and Cytherellidae, so that in his fine monograph he uses the term first leg in two quite different senses.
Giesbrecht and Hansen have shown that the mouth-organs consist of mandibles, first and second maxillae and maxillipeds; and Claus himself relinquished his long-maintained hypothesis that the last two pairs were the separated exopods and endopods of a single pair of appendages.
In 1892 he distinguished the former as those in which the first antennae of the male have both members modified for holding the female, and the genital openings of the female have a ventral position, sometimes in close proximity, sometimes strongly lateral; the latter as those in which the first antennae of the male are similar to those of the female, the function of holding her being transferred to the male maxillipeds, while the genital openings of the female are dorsal, though at times strongly lateral.
Of the corresponding pairs of appendages thirteen belong to the head and trunk, two pairs of antennae, one pair of mandibles, two pairs of maxillae, followed by three which may be all maxillipeds or may help to swell the number of trunk-legs to which the next five pairs belong.
In the maxillipeds and the trunk-legs it is common to find or otherwise easy to trace a seven-jointed stem, the endopod, from which may spring two branches, the epipod from the first joint, the exopod from the second.'
The second maxillipeds are developed into powerful prehensile organs, and the branchiae, instead of being connected with the appendages of head and trunk, are developed on the pleopods, appendages of the abdomen.
The most but not the only remarkable character lies in the first maxillipeds.
This mechanism as a whole is unique, although, as Sars observes, the epipod of the first maxillipeds has a respiratory function also in the Lophogastridae and Mysidae and in the cheliferous isopods.
The Hyperiidea are distinguished by having their maxillipeds never more than three-jointed.
In the thoracic series it is usual for one or more of the anterior pairs to be pressed into the service of the mouth, forming " foot-jaws " or maxillipeds.
AdvertisementIn the Schizopoda and Cumacea the line of division is less sharp, and the varying number of so-called maxillipeds recognized by different authors gives rise to some confusion of terminology in systematic literature.