anal sinus

The anal sinus varies from very shallow to rather deep.

The anal sinus can be found more or less near the suture.

The columella is narrow and the anal sinus hardly shows.

It is narrowly sinuate with the anal sinus pretty deep.

The anal sinus is large and rather deep.

The thick outer lip is notched at the anal sinus.

The light violaceous shell has a wide and shallow anal sinus.

The anal sinus is deep, about one-third of the way from the carina to the suture.

The anal sinus is varicose, and touches the sutural ramp.

The lip has a small infrasutural anal sinus.

The anal sinus is nearly central.

The anal sinus is situated in the infrasutural depression above the peripheral carina.

The outer lip has a narrow profound anal sinus on the subsutural ramp.

The lip lacks an anal sinus.

The teleoconch is flattened with a narrow keel posterior to the broad, anal sinus.

The narrow and smooth inner lip shows at its posterior end a shallow and broad anal sinus.

The anal sinuses end below in small valve-like folds, termed anal valves.

The outer lip is thin and arcuated, with the anal sinus situated below the sutural coronal.

The outer lip is not dentate and is inclined inwards with below a shallow anal sinus.

The anal sinus of the outer lip is not deep There is an opening in the infrasutural depression of the body whorl.

The fusiform shell is light-built with a deep, reverse "U-shaped" anal sinus on the shoulder slope and a tall, straight-sided conical spire.

The anal sinuses (rectal sinuses) are furrows in the anal canal, that separate the anal columns from one another.

The aperture is elliptical to oval in shape and it has a short to moderately long (e.g. Zemacies excelsa) siphonal canal and a deep anal sinus.