| 释义 |
epistom(e Zool.|ˈɛpɪstɒm, ˈɛpɪstəʊm|
The Latin form epistoma is also used.
[ad. mod.L. epistoma, f. Gr. ἐπί upon + στόµα mouth.]
An appendage in front of the mouth in Crustacea and certain insects. Also applied to similar parts in arachnids, molluscs, etc.
1852Dana Crust. i. 25 The base of the antennæ is thus cut off from the rest of the epistome. 1860Mayne Expos. Lex. Add. 1491/2 Epistoma, epistomis, epistomium, names for the space between the buccal cavity and origin of the intermediary antennæ in the Crustaceæ Maxillares; also for the hood of the Condylopa. 1878Bell Gegenbauer's Comp. Anat. 160 The mouth..is in one division overhung by a movable process—the epistom. 1880T. H. Huxley Crayfish 155 In front of the mouth, the sternal region which appertains, in part, to the antennæ, and, in part, to the mandibles, is obvious as a broad plate..termed the epistoma. 1897Parker & Haswell Text-bk. Zool. I. 328 (Molluscs), A small lobe—the epistome..—overhangs the mouth and lies between it and the anus. Ibid. 499 The head exhibits no segmentation: its sternal region is formed largely by a shield-shaped plate, the epistoma, nearly vertical in position. 1909Cambr. Nat. Hist. IV. 291 In Pterygotus there is a well-developed epistome..between the mouth and the front margin of the carapace. 1957Richards & Davies Imms's Textbk. Ent. iii. 587 In holoptic flies... The epistoma is the distal border of the face. Ibid. 752 Among Curculionoidea the reduced fronto-clypeal region is often termed the epistoma. |