Apectoichnus longissimus (Kelly et Bromley, 1984)

Diagnosis. Elongate borings, commonly circular in section, smooth-sided, straight or sinuous to contorted and intertwined, with or without a calcareous lining. The boring may change direction and cause a constriction of the tube but tubes are commonly of more or less constant diameter. May be solitary or gregarious.

Discussion. For discussion of the relevance of calcareous lining to ichnotaxonomy, see Donovan (2002).