Various Cyrtida with a complicated cephalic structure.
I) Acrobotrys (?) sp. Cr. Upper Cretaceous, California, station 1144; II) Acrobotrys sp., Lower Oligocene, Barbados; III) Botryocella sp. Middle Miocene, AMPH 6P; IV) Centrobotrys (=Lithobotrys) cf. cribrosa (Ehr., 1873), Upper Oligocene, JYN 16P; V, VI) Botryocella sp. O, Upper Oligocene, JYN V 16P (specimens with various development of pores and tubes); VII-XII) Artobotrys borealis (Cleve), surface sediment, Norwegian Sea, “Sevastopol” station 2104 (specimens in various positions; they differ in the form of the thorax and in the development of the peristome); XIII) form close to A. borealis, surface sediment, Indian Ocean, “Obj”, station 310 (VIII and IX at greater magnification than the others).