Drawing

Description:

Diplotheca costata Valkanov, 1970. The lorica is composed of two quite distinct chambers. The anterior chamber contains 18 longitudinal costae, each being formed by two costal strips with spatulate ends. A transverse costa containing six flattened costal strips forms the anterior ring and another composed of crescentic strips marks the boundary between the two chambers. The posterior chamber contains 10 broad and flattened costal strips with rounded ends. Each strip has a more opaque central region, on either side of which is a thinner region bearing a row of narrow transverse markings.