''Helicoconchus'' is a

microconchid The order Microconchida is a group of small, spirally-coiled, encrusting fossil "worm" tubes from the class Tentaculita found from the Upper Ordovician to the Middle Jurassic (Bathonian) around the world. They have lamellar calcitic shells, ...

genus that occurs in the Lower Permian of Texas. It forms small reef-like bodies of tubes branching from a common origin. The impunctate tubes are greatly elongated for microconchids and have occasional diaphragms with central pits. The tubes branch in two ways: budding from the tube wall and binary fission. They lived in shallow, normal marine environments.

References

Protostome enigmatic taxa Tentaculita Permian animals of North America {{permian-animal-stub