apical angle


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ap·i·cal an·gle

the angle between two plane surfaces of a prism.
References in periodicals archive ?
In conclusion the anatomical structure of the ACP, including the apical angle of the ACP triangle and its orientation in either a posterior or medial direction, are reported in this study and may serve as guides for planning clinoidectomy and aneurysm clipping.
the apical margin of the protibia of the female has a subcarinate ridge ending in an elongate, subacute uncus projecting posteriad, and has an acute mucro on the inner apical angle, partly concealed by 2 clusters of coarse setal brushes anterior and posterior to the mucro.
(ii) The shell dissymmetry D is strongly increasing with the growth-dissymmetry index [delta], less intuitively decreasing with the apical angle [alpha] and strictly independent of the differential-growth index [rho] and independent of the differential-growth index [rho].
(ii) the shell dissymmetry D is strongly increasing with the growth-dissymmetry index [delta] and, less intuitively, is decreasing with the apical angle [alpha];
Forewing light yellow, costal margin tinged slightly with grey, pagina with some irregular brown transverse lines, strongest one from inner side of apical angle to middle of posterior margin, dark brown oblique line starting below apical angle to metagonia, apical angle slightly round, outer margin curved, fringe scales grayish-yellow.
Whorl increase slow (coiling tightness usually >5, but at least 4.9) (Pseudavakubia) 10 2 Shell with distinctly acuminate apex and tapering spire (apical angle generally < 120[degrees], spire angle <60[degrees]) 3 -- Shell apex more rounded, spire aspect less tapering (apical angle at least 120[degrees], spire angle >62[degrees]) 4 3 Adult shell >5 mm, elongate, apex strongly acuminate, spire appearance less tapering; apical angle <100[degrees].
Small shell of 10 to 11 whorls with gradually tapering spire; whorls evenly rounded; sutures impressed; one fine, spiral thread just below suture and one fine thread just above suture; three larger, evenly spaced threads on central portion of whorl; interspaces wider than threads; apical angle of 26 degrees; aperture and slit not observed.
The species name is derived from the Latin words "rotundatus", referring to the forewing with a black round spot at the apical angle.
Parameres short, dorsocaudally directed, twice wider at basal half, narrower and subparallel sided at the apical half; in caudal view, apical half with profile rectangular with acute inner apical angle (Fig.
Area between lateral carinae of pronotum dark brown; two branches of outer apical angle of genital styles subequal; aedeagus with one small spine situated near basal third, directed caudally M.
Hindwing wider than forewing, brownish black, apical angle acute, outer margin oblique, fringe scales brown, area between costal margin and forewing grayish brown; Rs and [M.sub.1] stalked at 2/5, [M.sub.3] free from [CuA.sub.1].