Adaptation of a drawing of Tintinnopsis campanula by Fauré-Fremiet (1924) showing basic tintinnid morphology. Tintinnid taxonomy classically is based on characteristics of the lorica or shell. Species in the same genus share similar lorica architecture. For example, species in the genus Tintinnopsis all have lorica covered with small mineral particles, one end is closed, and do not have any clear (hyaline) spines or collars as part of the lorica.