Ewer, D. W. 1946. Sabella pavonina Savigny var. bicoronata Hornell and the genus Spirographis Viviani. Journal of the Marine Biological Association of the United Kingdom 26(3): 426-431,4figures.
A variety of Sabella pavonina Sav. described by Hornell as bicoronata has been found at Plymouth. It is characterized by the unequal development of the two sides of the branchial crown. The characters by which Sabella pavonina, its variety bicoronata and Spirographis spallanzanii may be distinguished are described. It is concluded that the genus Spirographis is not valid and that its species should be referred to the genus Sabella which is redefined.
