peristome


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Related to peristome: calyptra

per·i·stome

(per'i-stōm),
A groove leading from the cytostome in ciliates and certain other forms of protozoa.
Synonym(s): peristoma
[peri- + G. stoma, mouth]

peristome

(pĕr′ĭ-stōm′)
n.
1. Botany A fringe of toothlike appendages surrounding the mouth of a moss capsule.
2. Zoology The area or parts around the mouth in certain invertebrates.

per′i·sto′mal (-stō′məl), per′i·sto′mi·al (-stō′mē-əl) adj.

peristome

(pĕr′ĭ-stōm) [″ + stoma, mouth]
The channel leading to the cytosome or mouth in certain types of protozoa.

peristome

any structure that occurs around the mouth or opening of an organ.
References in periodicals archive ?
Peristome markedly oblique, almost tangential; aperture subcircular; columella concave, lacking dentition; outer lip notched at ends of spiral cords, somewhat thickened internally, but lacking both internal teeth and in-running ridges; interior of aperture nacreous, angled beneath external cords.
Peristome markedly oblique, more or less in one tangential plane; aperture D-shaped; columella more or less straight, but with a distinct, roundly trigonal tooth near its base; outer lip internally thickened, its edge flaring outward; inner thickening with 10 ridge-like denticles, that nearest columella largest, creating a U-shaped notch between it and columella tooth; interior of aperture nacreous, labral denticles not extending internally as in-running spiral ridges; exterior of outer lip subterminally thickened by a low collabral varix.
Conical straight free tube parts with well-developed transverse ornamentation in form of peristomes with the regularly undulating edge.
subacuminata in having closer-set axial ribs on the teleoconch, a less acuminate apex, less tightly coiled whorls, and a proportionally larger peristome.
The shell bears a large, wide aperture surrounded by a wide, thick, reflected peristome that may be free from (Fig.
The junction between a parental tube and the tube of a bud was always located immediately distal to a peristome win the parental tube.
Geastrum javanicum is characterized primarily by the velutinous, ephemeral mycelial layer, forming a cup under the saccate basidioma, fibrillose delimited peristome and subiculum.
Surrounding most of the opening of the pitcher is a swollen portion of tissue called the peristome or "lip.
Protoconch sculpture nude, or with difuse radial wrinkles; radial ribs thick, without spiral striation; pyramidal shell; peristome sharp, keel-like, resembling a sophonostoma Chellius piramidalis sp.
Peristome well developed; exostome yellowish, brownish towards base, lower outside ornamentation cross-striolate, upper outside ornamentation papillose, border broad, widened where ornamentation changes from cross-striolate to papillose; endostome hyaline to yellowish, basal membrane high, about 35-40% of endostome height, segments perforated, papillose, cilia 2-3, long, appendiculate at least in upper part of cilia, otherwise nodose.
On the other hand, the flexible peristome may allow for more variation in body fluid volume than has been appreciated, creating a potential need for fluid uptake.