Cyclaspis argus Zimmer 1902

Synonymy. Cyclaspis bistriata in Zimmer 1902; C. biplicata in Calman 1907; C. bistriata in Zimmer 1913, Stebbing 1913, Calman 1917.

Diagnosis. Female. Carapace finely pitted; 0.7 as high as long; eyelobe with distinct lenses; antennal notch open; anteroventral corner smooth. Pereonite 1 visible only from side. Pereonite 2 produced as large dorsal tooth directed anteriorly. Pleon with lateral articular pegs. Uropod peduncles longer than or equal to pleonite 6; endopod subequal to exopod; endopod with single seta medially; exopod with several setae. Male. Carapace less arched than in female, ridges present but fainter; eyelobe with more lenses; antennal notch oblique; appendages with more setae than in female. Uropod peduncles longer than pleonite 6, rami subequal.

Remarks. In the New Zealand Cyclaspis fauna, this species can easily be distinguished by the posterior pair of vertical ridges on the carapace.