04.1 Trivia arctica

04.1 Trivia arctica

Post-veliger juvenile shells probably T. monacha but almost identical to T. arctica. 1: 6.3 mm, typical gastropod spire and body whorl. 2: 9.6 mm spire nearly enveloped by body whorl, and ribs starting to develop. 3: 11.7 mm full grown juvenile with convolute shell concealing the spire. Orkney, 1975.