Dana, 1852
Length 10-17 mm. Head as long as pereonites I-III combined. P I simple (Cyllopus magellanicus 1). ART 2 of P I slightly shorter than distal ART combined; ART 5 and 6 elongate, 5 slightly broader than 6; ART 6 linear; posterior margin of ART 6 distally serrate; dactyl twice as short as ART 6. Posterodistal process of ART 5 of P II not reaching middle of ART 6. P V and VI much longer than III and IV, with thin distal articles; ART 5 longer than 4; 6 much longer than 5. P VII reaching only middle of ART 4 of P VI; ART 2 almost oval; 3-5 distal arts reduced.