Description of Calotheca

Cells solitary, lorica cone-shaped, constructed of six longitudinal costae composed of broad costal strips with T-joins; the posterior transverse costa consists of six obliquely orientated strips; protoplast is completely surrounded by overlapping longitudinal costal strips; marine; only known from warm water regions; Calotheca is closely related to Stephanacantha Thomsen, which has Y-joins in the mid lorica region.