Crinolina isefiordensis Thomsen, 1981. Cell solitary, planktonic, living in skirt-shaped lorica, open anteriorly and posteriorly. Protoplast 8 microns long and 5 microns wide, without chloroplast. Single flagellum 2-3 times protoplast length, surrounded by a collar of tentacles. Height of collar approximately 6 microns, maximum diameter of collar 13 microns Lorica 25-30 microns long, diameter at base 20-30 microns, diameter at neck constriction 10-13 microns Longitudinal costae (12) 15-16, each composed of 6-7 costal strips. Two transverse costae. Longitudinal costae form spines at the anterior end of the lorica. Each spine is composed of two costal strips. Posteriorly the longitudinal costae project slightly beyond the transverse costal ring.