Risso, 1822
Body almost globular (Phrosina semilunata 1). Males much smaller than females. Heads produced into two rostral points. In females ANT I very short, ANT II absent. Pereonites I and II fused. P III-VI clearly subchelate (Phrosina semilunata 3). P V-VI much longer than other. P VII with well-developed ART 2, distal arts almost completely reduced.
Monotypic.
Phrosina semilunata Risso, 1822