Epistoma

E`pis´to`ma


n.1.(Zool.) The region between the antennæ and the mouth, in Crustacea.
References in periodicals archive ?
1] como los laterales, el tercer par de maxilipedos a modo de fondo y la region del epistoma como pared de contencion de este material.
1), notably the swollen proboscis, the absence of ocelli, reduced eye size, the prominent epistoma, reduced thoracic setae, wings strongly truncated and narrow, and legs elongate.
La frente del macho fue moderadamente concava desde el margen del epistoma hasta cerca de los ojos.
5 veces la longitud del ischium (Figura 4F); canal eferente parcial mente cerrado por la espina del angulo yugal y por el lobulo lateral del epistoma.
Coccotrypes 11 10(9) Superficie pronotal brillosa con reticulaciones no muy visibles, muchas punciones discales acompanadas por una elevacion transversa; frente del macho con una impresion transversa fuerte de epistoma a nivel superior de los ojos; vestidura de surcos interestriales de setas aplanadas cortas y robustas; color marron rojizo; longitud de 1.
Aleuas Zygodistron Frontal carinae Converging from epistoma Converging but uniting to fastigium, where they in a single one above may come together insertion of antennae.
Head with epistoma nearly flat, punctured; clypeus nearly semicircular, faintly truncate or feebly sinuate at middle, widely rounded at sides, quite thinly bordered, edge thickened at middle, elongately bristled at sides; genae strongly developed, abruptly angulate, not deflexed, bristled, protruding much more than eyes; latter medium size; frontal suture finely impressed, not at all tuberculate.
Head with epistoma feebly convex on disc, finely subregularly sparsely punctured, punctation somewhat denser and coarser distally; clypeus faintly sinuate at middle, rounded at sides, almost thickly bordered, the edge upturned; genae subauriculate, obtusely angulate, elongately ciliate, distinctly protruding more than eyes; frontal suture finely impressed, nearly faint at middle; front relatively somewhat densely punctured.
3 times as wide as first flagellomere, without facial carina, lower 1/3 of facial ridge with small setae, lower parafacial brown, epistoma distinctly situated behind frontal angle in profile, gena black, with grey pruinosity, gena about 3/5 of eye in height, genal hairs black, and postgena setae light-yellow, prementum without pruinosity, slightly shining, about 2.
2 times as long as pedicel, the basal 1/4 of arista becoming thick, the basal 3/4 of arista plumose, the longest hairs subequal to first flagellomere in width, facial carina lower and narrow, lower 1/3 of facial ridge with small setae, lower of parafacial brown, epistoma distinctly situated behind frontal angle in profile, gena black, with grey pruinosity, genal height about 1/3 of eye height, genal hairs black, and postgena with sparse light-yellow hairs, occiput lateral area with hairs, prementum without pruinosity, shining, about 2.
clarki, Griphaostrea Corner grande, Vaginulina yadei, Robulos munsteri, Epistoma caracola; del conjunto K2c citan Siphogenerinoides sp.
5b) (length and width: 160 x 170 [micro]m) with sclerites strongly sclerotized with the exception of the epistoma (weakly sclerotized).