adapical

adapical

[‚ad′a·pi·kəl]
(botany)
Near or toward the apex or tip.
References in periodicals archive ?
First teleoconch whorl sculptured by somewhat sinuous axial pliculae; 3 spiral cords arise during second whorl and a fourth, beneath the adapical suture, during whorl three; sculpture of subsequent whorls comprising 4 (rarely five) spiral cords (not counting that level with abapical suture), these crossed by somewhat irregular, prosocline axial pliculae (30-40 on last adult whorl); cords with scale-like nodules where crossed by pliculae, those on uppermost (subsutural) cord frequently larger; intervals between cords slightly wider than cords themselves; cord intervals on last adult whorl occasionally with a weak intermediary cord.
20 axial pliculae; 3 spiral cords develop during second whorl (lowest level with abapical suture), and a fourth arising beneath adapical suture near end of whorl; subsequent whorls with further cords arising through intercalation; penultimate whorl with 7-9 cords, sometimes alternating a little in strength, sometimes not; seventh cord usually peripheral; cords well defined, equal to or wider than their intervals.
5 whorls; sculpture strongly cancellate; first whorl initially sculptured only by axial pliculae, relatively widely spaced at first, but becoming more close-set toward end of first half whorl; 3 spiral cords develop during first whorl, one at mid-whorl, one between this and adapical suture and the third level with abapical suture; that at mid-whorl strongest and becoming peripheral cord of later whorls; cords become progressively stronger with growth, a fourth appearing below adapical suture during third whorl; axial pliculae more widely and regularly spaced from second whorl onward; pliculae cross cords producing angular nodules at intersections; in final quarter of last adult whorl an additional intermediary spiral cord arises between each of the primary cords (Fig.
56A, C): White to translucent white, strongly exsert; diameter 260280 um; apical beak scarcely evident; surface evidently smooth; terminal lip roundly angled between mid-whorl and adapical suture.
5-2 times as numerous as peripheral projections; interval between peripheral cord/keel and abapical suture progressively deeper and more channelled with growth; development of remaining spirals between adapical suture and periphery variable, sometimes distinct, sometimes obsolete; axial sculpture becoming less obvious with growth; apical whorls (not first) somewhat cancellate, becoming more foveolate with elongate D-shaped pits on later whorls; pliculae in supra-sutural sulcus usually stronger and less close-set than those above peripheral keel.
Apical surface of teleoconch sculptured by close-set axial riblets, these becoming much weaker at periphery and scarcely evident at all on base except around and within umbilicus; base also with traces of spiral striation in some specimens; aperture suboval, somewhat obliquely descending outwards; outer lip of adult frequently thickened basally, but sometimes also retaining a membranous periostracal fringe; adapical portion of outer lip often flattened; upper part of columella lip reflected; umbilicus of moderate width, not obscured to any appreciable degree by reflected columella lip.
1 mm, initially somewhat smooth, but with distinct axial riblets developing along adapical suture during first whorl, these extending to abapical suture on second whorl (Fig.
In terms of shell features, Capitina is characterised by the brown spiral lines on the adapical surface, wrinkled sculpture and thickened apertural lip of the adult.
Spiral ridges thinner than axials in intervals, expanding on ribs to form angular nodules, ridges nearly equal in strength, adapical row slightly the stronger, abapical one slightly weaker; first two whorls with two rows of nodules plus a third usually beginning to develop above suture, later whorls with three main rows of nodules, plus a weak ridge immediately below suture; last whorl with a shallow waist-like furrow at base of rostrum containing a thin ridge, strengthening and bearing angular nodules on dorsum; rostrum forming a moderate fasciole, which bears 3 ridges weakening anteriorly, the upper 2 with angular nodules.