It does not seem to be cosmopolitan, but a geographically well-defined species from the North Atlantic. [details]
Prosycum primordiale nomen nudum Haeckel, 1870, Ascetta primordialis Haeckel, 1872 [details]
BMNH 1931.10.28.2 (holotype/alcohol). [details]
BMNH 1999.9.16.20 (holotype/alcohol) [details]
ZMB 1306 (suggested lectotype/alcohol). Naples, PMJ. Inv. Nr. Porif. 154 (type/alcohol) [details]
BMNH 1910.1.1.790 (holotype/alcohol) BMNH 1910.1.1.789 (paratype/alcohol). [details]
The species described by Bowerbank as L. contorta was probably a specimen of L. complicata, thus the species ... [details]