Synonyms for subsutural or Related words with subsutural
Examples of "subsutural"
Whorls simple, aperture elongate, columella simple and thickened,
band present, often ornamented.
Shell slender with a noded
band. The variably decorated remainder of the whorls together appears as an ornamented belt.
This genus was proposed by Vella in 1954 for species resembling "Splendrillia", but having a different protoconch, another
fold and showing a stromboid notch
Characteristic for this species is that the spiral sculpture shows 4-5 well-spaced grooves per whorl. Furthermore, the
cord is feeble.
Shells of "Terebra armillata" can reach a length of . These shells are very variable in color and pattern. Usually they show a dark gray or brown color. The
band is white, with brown spots.
The anal sulcus can be linked on the edges to a fasciole, a spiral band on the shell, formed by successive growth lines. It can also have a
callus (such as in Clathrodrillia callianira).
The spire is moderately elevated. The teleoconch contains fine spiral cords. The
cord sometimes contains nodules. The open, but not very broad umbilicus has no callus. The radula contains a broad latero-marginal plate.
The suture also provides a sort of geographic marker from which one can refer to the positioning of patterning or sculpture, where that is relevant: for example some species have a darker or lighter
band on the shell.
The whorls increase rapidly in size on this very narrow shell. The nodular axials are more or less restricted to the periphery. The
fold is obsolete. There are 21 - 22 strong nodules per whorl.
The height of the conico-turbinate shell attains 10 mm, but is usually less than 5 mm. Its typical characteristic is the
angulation and the cord around the umbilicus formed by double rows of rounded tubercles.
The smooth protoconch is bluntly rounded and paucispiral, consisting of two whorls. The sinus is
, steeply descending and then produced forward to meet the arcuately produced outer lip. The vestigial operculum may reflect an archaic condition.
The shell varies in altitude, in the presence or absence of the yellow
line and especially in the characters of the umbilicus, which is either closed, or more or less open. This is not dependent on age.
The type of this genus is "PIeurotoma silicata", of Aldrich, a very remarkable and isolated species occurring in the Lignitic Eocene of the Gregg's Landing beds of Alabama. The beaded
collar, subjacent depression and swollen and finely ribbed lower parts of the two whorls immediately below the protoconch are lost completely on the larger whorls, though the
collar can be feebly traced as a slightly tumid line gradually descending further below the suture with the growth of the shell. Besides "silicata", the genus will include the much stouter "PIeurotoma roscoei" Harris, from the same horizon.
The white shell is small, globose and umbilicate. It is rather thin and shining. It is concentrically irregularly ribbed. The interstices are grooved, concave and transversely very faintly striate The ribs are spotted remotely with rose red. The altitude is about equal to the diameter. The
rib is frequently nodose. The umbilicus is crenated within the margin.
The length of an adult shell varies between 7.4 mm and 12.5 mm. The whorls are not shouldered. The axial ribs do not undulate on base. The spiral threads are microscopic or absent, except on the rostrum. The terminal varix is strong. The
region is not contrastingly dark. The base of the body whorl shows a row of weak white pustules.
There is great variation in color in this species. In some specimens red predominates, in others green. And often the general effect is an olive shade. There is usually a
series of light and dark dashes. The numerous narrow red spiral lines are characteristic.
This form is similar in general appearance and form to "Tegula quadricostata". The spire is either elevated or rather depressed. The sutures are deeply canaliculate. The body whorl is encircled by three prominent, equidistant carinae, one
, composed of rounded or
The shell color is typically a light yellowish-brown with irregular lighter,
maculations, very occasionally with pink or purple beads or rarely a stripe. It has a peripheral circle of alternating chestnut and white spots. The ribs of the base are minutely articulated with chestnut and white.
The whorls are not shouldered. The axial ribs do not undulating on base and are not weakening below the suture. The spiral threads are microscopic or absent, except on the rostrum. The base of the body whorl lacks a row of pustules The terminal varix is strong. The
region is not contrastingly dark.
The size of the shell varies between 20 mm and 40 mm. The umbilicate shell is typically more elongated than "Lunella coronata" with an altitude about equalling the diameter. It is finely granulose all over, with
and coronal series of tubercles, and sometimes one or two additional series upon the median part of body whorl.
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