Figs 17–23. Trigonaspis melvillea. TEM whole mounts from the Weddell Sea, Antarctica. 17 in Coccolithophorids in Polar Waters: Trigonaspis spp. Revisited

Figs 17–23. Trigonaspis melvillea. TEM whole mounts from the Weddell Sea, Antarctica. 17 – whole cell with flagella and a curled up haptonema positioned inside a corona of distinct flagellar pole coccoliths; 18 – complete cell with flagella and partly extended haptonema; 19 – detail of the distal termination of a flagellar pole coccolith (from Fig. 18); 20 – rimmed body coccoliths supporting densely packed layers of crystallite groups (from Fig. 18). Unmineralized under layer scales are pointed out; 21 – detail of unmineralized termination of flagellar pole coccolith. The still remaining organic matrix clearly reveals the triangular shape of a crystallite group; 22 – detail of body coccolith calcification. Notice that the triangles are united to form hexagonal rings; 23 – uncalcified specimen showing body coccolith base plates and under layer scales (arrows).