“Zemitrella n. gen. Type: Lachesis sulcata Hutton.
Here may be grouped the remaining New Zealand Pyrenids (except those placed in Anachis); choava, pseudomarginata, stephanophora, websteri, laevigata, rosea, the type, and (provisionally) Atilia daemona Webster. There is indication that more than one shell type is included here, but there is gradation, and till the fossil forms are better known I prefer not to split further. Marshall's Mitrella inconspicua (Trans. N.Z. Inst., vol. 50, p. 266, 1918) and some undescribed Tertiary species (e.g., Suter's “Alcira n. sp.”—N.Z. Geol. Surv. Bull. No. 20, pp. 89, 93, 1918) belong to this group, all the members of which show an oblique plait at the base of the pillar. Choava has the plait subobsolete, but all the others show it strongly, especially in juvenile shells.
The Neozelanic species of Anachis are divisible into two groups, one containing small shells with short beak, and the other—restricted to the Tertiary—larger shells with distinct canal. Neither of these exactly matches with Pyrene gemmulifera Hedley (the type of Retizafra) which is a minute Mitrithara-like shell from the Capricorn group, nor with the genotypes of any of the cancellate genera outlined by Iredale in Proc. Mal. Soc., vol. 12, pt. 1, p. 33, 1916. The forms of both series seem to be sublittoral dwellers of southern development, and as no other austral group is suitable I provide names.”
(Finlay, 1927: 431)
Species within the genus Zemitrella include: