Genus Nannastacus Bate, 1865

Diagnosis (emended by Watling 1991b): Carapace anteroventral corner large, acute, strongly projecting; ocular lobe divided, eyes when present located dorsolaterally; branchial siphon unite medially; pseudorostral lobes short, directed slightly upward; antenna 1 peduncle article 2 usually with process, subequal in length to the peduncle of the article 3; female maxilliped 3 and pereopods 1–2 with exopods, occasionally missing on maxilliped 3; male maxilliped 3 and pereopods 1–4 with exopods; uropod peduncle in male shorter than or equal length to the pleonite 6; uropod exopod basal article very short often submerged in peduncle, exopod shorter than its terminal seta.