Article: Abnormal growths in some Devonian goniatites

Specimens of Sobolewia from the Givetian of Cornwall and Algeria are described which show a regular pitting on the internal moulds. The same phenomenon is noted on an Algerian Eifelian goniatite and also on German specimens of Sellanarcestes from the Emsian and Eifelian and on an Eifelian Anarcestes. The pits, which are commonly arranged in sub-radial rows, are interpreted as formed in life as mound-like growths on the inside of the anterior part of the body chamber shell, but not along the apertural margin. Several hypotheses on their origin are discussed.