Spiral shell

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any shell in which the whorls form a spiral or helix.

See also: Spiral

References in periodicals archive ?
The nautilus, a spiral shell with pale, pearly chambers, is one of the finest examples of natural beauty and elegance.
This is inspired by the spiral shell with a pale pearly partition, which includes a series of expanding, concentric arcs.
Other topics include image processing and artificial neural networks for the automated identification of plant species from leaf outlines, a genome-wide association study of biological shape based on elliptic Fourier analysis with a case study in rice gain shape variation, evolution and devolution in the spiral shell growth of gastropods, comparing robust generalized superimposition methods using three-dimensional facial images, and Fourier descriptors in a quantitative analysis of whole body outlines.
The internal structure of the multichannel cyclone with a spiral shell (b): 1--multichannel cyclone with a spiral shell; 2--curvilinear semi-rings; 3--air (gas) flow inlet; 4--air (gas) flow outlet
Curved timber trusses, made of strips of oak laminated together, create the skeleton of the spiral shell shape, attached to an elliptical concrete frame below.
Contemporary reports said the basin tank reservoir, also connected to Nelly's Moss lakes, was shaped conically in the pattern of a spiral shell, but without any photographs or official records in existence, experts have never known for certain the exact design.
By the time Susan finished this remarkable, beautiful description of the pure sensations of the source of the remedy she needed, we knew that it was a mollusk, with a spiral shell.
In fact, Lari dreamt up the plot to her new book, First Aid For Fairies And Other Fabled Beasts, while watching her daughter Gowan play with a plastic toy pony and a spiral shell they had picked up on a beach-combing trip.
But slowly the sun burnt off the mist and later, near the top of the slope you found an ammonite's spiral shell, nearly whole, a swirling vortex in chalk, and you knelt and began to chip at it.
I have yet to see it,but the mind conjures up images of a pair of enormous antennae looming over the horizon,followed by a spiral shell that causes chaos on the A55 when it becomes lodged under the flyover at Slaters roundabout.
Maybe the only project to combine growth with the persistence of functionality in urban structures is imaginary, like the tower of Babel, pictured as a sea snail with a growing spiral shell.